UNIVERSITY OF CALIFORNIA COLLEGE OF AGRICULTURE AGRICULTURAL EXPERIMENT STATION BERKELEY, CALIFORNIA A RATING OF CALIFORNIA SOILS WALTER W. WEIR AND R. EARL STORIE BULLETIN 599 JANUARY, 1936 UNIVERSITY OF CALIFORNIA BERKELEY, CALIFORNIA CONTENTS PAGE Introduction 3 27 Storie index 3 28 Method of rating 4 29 Soil groups 7 30 Soil types and phases 9 31 Grades 10 32, Arrangement of sections ... 11 33. 1. Alturas area 13 34, 2. Anaheim area 16 35, 3. Auburn area . : 19 36. 4. Barstow area 21 37. 5. Big Valley area 23 38. 6. Bishop area 25 39. 7. Brawley area ........ 28 40. 8. Capistrano area 31 41. 9. Chico area 34 42. 10. Clear Lake area 36 43. 11. Coachella Valley area . ... 38 44. 12. Colusa area 40 45. 13. Concord area . . . . \. . . 44 46. 14. Dixon area . . . .• 46 47. 15. El Cajon area 48 48. 16. El Centro area 50 49. 17. Eureka area 52 50. 18. Fresno area 55 51. 19. Gilroy area 58 52. 20. Grass Valley area 59 53. 21. Healdsburg area 62 54. 22. Hollister area 64 55. 23. Honey Lake area 67 56. 24. King City area 70 57. 25. Lancaster area 74 58. 26. Livermore area 76 59. PAGE Lodi area 79 Los Angeles area 82 Madera area 85 Marysville area 87 Merced area 91 Modesto-Turlock area .... 92 Napa area 96 Oceanside area 99 Oroville area 102 Pajaro Valley area 104 Palo Verde area 106 Pasadena area 108 Paso Robles area Ill Placerville area 113 Red Bluff area 115 Redding area 117 Riverside area 119 Salinas area 122 San Fernando Valley area . . 125 San Jose area 126 San Luis Obispo area .... 128 Santa Maria area 129 Santa Ynez area 132 Shasta Valley area 135 Stockton area 136 Suisun area 139 Ukiah area 142 Ventura area 144 Victorville area 146 Visalia area 149 Willits area . . . ". 151 Woodland area ....... 153 Yuma-Wellton area 156 A RATING OF CALIFORNIA SOILS' WALTER W. WEIR 2 and R. EARL STORIE 3 INTRODUCTION A great variety of soil conditions are found in California, a condition brought about by the wide range of natural phenomena which are cer- tain to occur in an area so large. The multiplicity of geologic formations, the varied physiographic features, and the wide range in climatic condi- tions have given rise to such a variety of soils that more than 250 separate and distinct soil series 4 have been recognized and mapped in the soil surveys of California. Although the different soils are more or less regional in their distribu- tion over the state and usually in an obviously logical arrangement within the region, there is nevertheless an intricate intermingling of soil series in any given area. This may be readily observed from an ex- amination of the maps of any of the more than 80 soil surveys in Cali- fornia. Storie Index. — The necessity for a numerical expression of the rela- tive agricultural value of these various soils led Storie 5 to prepare what has become generally known as the "Storie index" method of soil eval- uation. In the following pages will be found a rating, by the Storie index method, of each soil type found in each of 59 soil-survey areas in California. 6 See figure 1 for the location of the 59 areas. For convenience, the soil-survey area has been taken as a unit for this rating and each area is treated independently. The areas are arranged alphabetically and the soil types are listed in each area in the order in which they are described in the corresponding soil-survey report. i Received for publication May 7, 1935. 2 Associate Drainage Engineer in the Experiment Station. 3 Assistant Soil Technologist in the Experiment Station. 4 A soil series is defined by Shaw as a grouping of soils having the same character of profile, the same general range in color, structure, consistence and sequence of horizons, the same general conditions of relief and drainage, and a common or similar mode of formation. (Shaw, C. F. A glossary of soil terms. Amer. Soil Survey Assoc. Bui. 9:23-58. 1928.) 5 Storie, R. Earl. An index for rating the agricultural value of soils. California Agr. Exp. Sta. Bui. 556:1-44. 1933. 6 About 20 soil-survey areas, including 7 on reconnoissance scale, are not included in this analysis because in part the same territory is covered by more than one survey. [3] 4 University of California — Experiment Station Soil Surveys. — Table 1 is an alphabetical list of the counties in this state with the soil-survey area or portions of areas included within the county. 17. Eureka 18. Fresno 19. Gilroy 20. Grass Valley 21. Healdsburg 22. Hollister 23. Honey Lake 24. King City Lancaster 26. Livermore 27. Lodi 28. Los Angeles 29. Madera 30. Marysville 31. Merced 32. Modesto-Turlock Napa 34. Oceanside 1. Alturas 2. Anaheim 3. Auburn 4. Barstow 5. Big Valley 6. Bishop 7. Brawley 8. Capistrano 9. Chico 10. Clear Lake 11. Coachella Valley 12. Colusa 13. Concord 14. Dixon 15. El Cajon 16. ElCentro 35. Oroville Pajaro Valley 37. Palo Verde 38. Pasadena 39. Paso Robles 40. Placerville 41. Red Bluff 42. Redding 43. Riverside 44. Salinas 45. San Fernando Valley 46. San Jose 47. San Luis Obispo 48. Santa Maria 49. Santa Ynez 50. Shasta Valley 51. Stockton 52. Suisun 53. Ukiah 54. Ventura 55. Victorville 56. Visalia 57. Willits 58. Woodland 59. Yuma-Wellton ^ & .& Fig. 1 — Soil survey areas in California Some of these survey reports are old, dating back to 1900, and copies are no longer obtainable except as references in the larger public li- braries ; many are available for free distribution to those who are inter- ested ; and a few of the more recent surveys are still in manuscript form or in press. Method of Rating. — In order that the reader may readily familiarize himself with the methods of determining the index rating of a soil, table Bul. 599] A Rating of California Soils 2 is reproduced from Bulletin 556. This table shows, in compact and abbreviated form, the three essential factors considered in the rating, together with the values assigned to the various subdivisions of each factor. TABLE 1 California Counties with Names of Soil Surveys that Include Any Portion of the County County Soil survey County Soil survey Alameda Livermore* Alpine Placer Plumas Riverside Auburn, Marysville* Amador Butte Chico, Colusa*, Oroville, Red Bluff* Coachella Valley, Palo Verde, Riverside Lodif, Marysville*, Suisun Colusa*, Marys ville*, Oro- ville, Woodland* Concordf , Livermore* San Bernardino Anaheim, Barstowf, Pasa- Capistrano, El Cajon, El Dorado Placerville Fresno* Colusa*, Oroville Eureka Brawley, El Centro, Palo Verde, Yuma-Wellton Bishop Lancaster, Paso Robles Glenn Lodif, Modesto-Turlock*, Humboldt San Luis Obispo San Mateo Obispo, Santa Maria Santa Barbara Clear Lake Alturasf, Big Valley, Honey Lake Anaheim, Lancaster, Los An- geles, Pasadena, San Fer- nando Valley*, Ventura Madera* Redding* Stanislaus Modesto-Turlock * Ukiah*, Willits Merced*, Modesto-Turlock* Alturasf, Big Valley Bishop King City, Pajaro Valley*, Salinas Napaf Auburn, Grass Valley Colusa*, Red Bluff* Trinity Tulare Visaliaf Yolo .... Yuba Marysville* * Surveys which are no longer available for distribution or sale and which can be found only in the larger public libraries. f Surveys which are either in press or in manuscript and not yet available for distribution as this manuscript goes to press (January, 1936). The numerical values assigned to the factors in this table are per- centages of what may be considered as an "ideal" or "most desirable" condition. The soil index rating, which is also a percentage, is computed by multiplying the three factor values, that is, soil index rating = factor A X factor B X factor C. University of California — Experiment Station TABLE 2 Soil Eating Chart — For Eating or Judging the Agricultural Value of Soils* (Soil index rating = factor A x factor B x factor C) Factor A, rating of soils on basis of character of profile Factor B, rating of soils on basis of surface texture Factor C , rating of conditions that modify agricultural uses of soil Soil group Rating, per cent Texture Rating, per cent Condition Rating, per cent I. Unweathered or slightly weathered secondary soils II. Moderately weathered secondary soils III. Strongly weathered secondary soils with dense clay subsoils, developed on uncon- solidated parent ma- terial IV. Maturely weathered secondary soils with hardpan: Hardpan less than 1 foot 1-2 feet 2-3 feet 3-4 feet 4-6 feet V. Strongly weathered soils having dense clay subsoils resting on con solidated material VI. Primary soils under laid by bedrock: Depth less than 1 foot l-2feet 2-3feet Over3feet 95-100 80-95 40-80 5-10 10-20 20-30 30-40 40-60 20-40 20-25 25-40 40-60 60-70 Medium-Textured : Fine sandy loam Loam Silt loam Sandy loam Coarse sandy loam Loamy sand Medium-Heavy Tex- tured: Silty clay loam Clay loam Heavy-Textured : Silty clay Clay and adobe clay.... Light-Textured : Very fine sand Fine Sand Sand Wind-blown sand Gravelly or Cobbly: Gravelly fine sandy loam Gravelly loam Gravelly silt loam Gravelly sandy loam.. Gravelly clay loam Gravelly clay Gravelly sand Stony: Stony fine sandy loam Stony loam Stony silt loam Stony sandy loam Stony clay loam Stony clay Stony sand 100 100 100 95 90 65 50-70 20-70 70 70 70 65 55 35 20-30 70 70 70 65 60 35 10-40 Drainage: Well drained Fair drainage Moderately water- logged Badly water-logged . Alkali: Alkali-free Slightly affected Moderately affected Strongly affected Acidity: According to degree Infertility: According to degree. Stratified Subsoil Shallow Phases of Alluvial Soils: 2 feet deep 3 feet deep Eroded Soils: Moderate Badley Steep Phases: Fairlysteep Steep 100 80-90 40-60 10-40 100 90 5-25 60-95 60-95 60-95 50-60 70 80-95 30-80 60-80 20-30 Miscellaneous nonagricultural material, Group VII Type Description Rating, per cent Rough mountainous land 5-10 Scabland 5-10 Rough broken land Steep slopes, eroded slopes, gullies, and canyon walls 5-10 Riverwash 1- 5 Placer diggings and tailings 1- 5 Tidal lands 1- 5 Coastal beach and dunesand 1- 5 Rough stony land 1- 5 * From: Storie, R. Earl. An index for rating the agricultural value of soils. California Agr. Exp. Sta. Bui. 556: 38. Table 4. 1933. Bul. 599] A Rating of California Soils Soil Groups. — Table 3 describes briefly the seven soil groups into which the soils fall on a basis of their profile development, and table 4 lists all of the recognized soil series of the state and designates the group into which they fall. Under the designation "soil group," the mode or TABLE 3 Soil Grouping on Basis of Profile Characteristics Group No. Group Description Surface relief I Unweathered or slightly Loose and friable soil, 6 ft. or more Flat or gently sloping alluvial weathered secondary deep flood plains soils II Moderately weathered Deep soils having compact subsoils Terraces, benches, or valley secondary soils and moderate accumulation of clay floors; topography may be in subsoils ; not so permeable as soils somewhat irregular owing to of group I eroded nature of terraces III Strongly weathered sec- Deep soils having dense clay subsoils; Terraces or benches which may ondary soils with dense slowly pervious to water; loose, un- be somewhat eroded, though clay subsoils, developed consolidated alluvial parent ma- they may be flat on top on unconsolidated par- terial ent material IV Maturely weathered sec- Soils with hardpans impervious to Flat valley floors, elevated ter- ondary soils with hard- roots or moisture; usually with races, eroded terraces; surface pan dense clay layer overlying hardpan ; soil material below hardpan may be friable may have "hog wallows" V Strongly weathered soils Soils with dense clay subsoils having Usually occupy high eroded having dense clay sub- hardpan-like substratum; imper- marine terraces on the coastal soils resting on consoli- vious subsoils; subject to erosion plain dated substratum VI Primary soils underlaid Soils formed from disintegration and Rolling, hilly, or mountainous by bedrock decomposition of underlying bed- rock; bedrock usually encountered 1 to 6 ft. below surface; steeper slopes erode badly; may be shallow or stony (hill lands) VII Miscellaneous Nonagricultural or nonarable land types method of formation, the age or degree of profile development, major climatic influences, and topography are considered. Each of these fea- tures, although not appearing as a separate item in the index, is never- theless given proper consideration in the values assigned for factor A. When unusual conditions of profile or topography occur, which make any particular soil strikingly unlike the other soils of the same group, adjustment can be made by altering the values given in either factor A or factor C. Such conditions are rare. University of California — Experiment Station TABLE 4 Soil Series of California Listed Alphabetically, with Their Positions in the Six Groups Series Group Series Group Series Group Series Group Adelanto Agate Agueda Aiken Alamo Aliso Altamont Alviso Ambrose* Anderson Anita Antelope Antioch Arbuckle Arnold Arroyo Seco. . Atascadero Avar Bale* Ballard Barron Barstow Bayside Baywood Bear Bear Creek*... Belle vista Bieber Bishop Bixler* Botella Buntingville. Butte Cachuma Cajon Calistoga* Canby Capay Carlsbad Carneros* Carrizo Carson Cayucos Centerville Chamise Chino Chualar Churchill Clayton* Clear Lake Climax Coachella Cole Columbia Commatti Conejo Contra Costa Coombs* Coquille Corning Corralitos Cuyama Daggett Danville Daulton Delaney Ill V I VI IV III VI I III II II V III I VI I V VI II II II IV I I I II IV V I I II VI III I I V III VI III VI III V I II IV II I VI I II I II I VI III I III I II II I VI I Delano Delhi Denverton Diablo Diamond Spring; Dinuba* Docas Domino Dublin Ducor Dunnigan Egbert Elder Elkhorn Elna. Empire Encina Escondido Esparto Exeter Fallbrook Fancher Farwell Feather Ferndale Foster Fresno Fullerton Galveston Garey Gazelle Gila Gleason Gloria Goldridge Gould Greenfield Gridley Hames Hanford Hartley Herdlyn* Hesperia Holcomb Holland Holtville Honcut Hovey Huerhuero Hugo Imperial Indio Johnstonville Reefers Kettleman Kimball Kirkwood Klamath Kneeland Konokti Laguna Lahontan Landlow LasFlores LasPosas Lassen II I III VI VI III II IV I II III I I II IV III VI VI II III VI IV I I I I IV II I II IV VI IV VI V III III III III I III VI I I II III VI I I II III VI III III III VI VI II V V VI VI Lewis Lindsey Linne Livermore Lockwood Los Angeles LosOsos Lynndyl Madera Manzanita... Marcuse Maricopa Marina Mariposa Marsh Creek Marvin Marysville May wood Maxwell* McClusky Media Melbourne... Meloland Merced Merriam Metz Mocho Modesto Modoc Mojave Mono Monserate Montague Monterey Montezuma . MoroCojo Nacimiento . Niland Nord Norman Norris* Oakdale Oakley Ojai Olcott Olivenhain ... Olympic Orland Osage* Oxnard Pajaro Panoche Pentz Pinole Pit Placentia Pleasanton. Pond Poplar Porterville... Preston Ramada Ramona Redding. Rhonerville Rincon IV II VI I III VI VI II IV III III II I VI I II IV I III III VI VI I III III I I III II III IV V IV VI III VI VI II II III VI I I II III V VI II III I I I VI III I III II II II II I II IV II II Rocklyn Rosamond .... Rositas Ryde* Sacramento . Salinas Salsipuedes.. San Gabriel San Joaquin San Marcos San Ramon* San Ysidro.. Santa Cruz Santa Lucia . Santa Rita .... Santa Ynez Santiago Seville* Shasta Shedd Sheridan Sierra Siskiyou Sites Solano Soledad Sorrento Stacy Standish Stockpen Stockton Sunol Sunrise Superstition. Surprise Sutter Tangair Tassajero Tehama Tierra Tijeras Traver* Troy* Tujunga Tulare Tuscan Ulmar Underwood.. Vallecitos Vina Visalia* Vista Wapato Watsonville . Westport Whitney Willits Willows Woodrow Wyman Yermo Yokohl* Yolo Ysidora Zaca Zamora * Provisional names of new series in unpublished reports. Bul. 599] A Hating of California Soils 9 In some cases the assignment of a soil to a particular soil group is a matter of individual judgment and in a few cases they may be placed in different groups in different areas. Since all of the soils are not equally well known because of rare or infrequent occurrence or because soils having slightly different characteristics are sometimes given the same name in different areas, some leeway in assigning factor A values must be allowed. In each case the description of the soil as found in the soil- survey report for the particular area is used as a basis for determining its rating. An important part of making a soil survey is the correlation, by the Correlation Committee, of the soils of the area with the soils of all pre- viously mapped areas in order that similar soils, regardless of their location, will be given a common series name and that the same name will not be given to two dissimilar soils. The science and technique of soil surveying, and the concept of what constitutes fundamental soil char- acteristics, have undergone progressive development since the earlier surveys, with the result that notwithstanding the vigilance of the Cor- relation Committee, many of the older surveys describe soil series which do not conform to the present concept of that series. The grouping as listed in table 4 is in conformity with the most recent concept of the vari- ous series ; and whenever, in the tables below, the designated soil group is not in conformity with that of table 4, the reason should be obvious. To rate a soil properly by the Storie index method, one must know the texture, degree of development of profile, depth to hardpan or bedrock, and drainage or erosion conditions. With these facts known, the rating is a comparatively simple matter, but some difficulty is encountered in rating soils which are inadequately described or which are so inclusive as to leave doubt as to true or typical conditions. For the purposes of this paper, certain assumptions have been neces- sary where complete data were not available. For example, a primary or group-VI soil may be described as being developed on bedrock found at a depth of 2 to 6 feet. In this case 4 feet is taken as the average depth of this soil and the rating made accordingly, but of course the rating given does not properly rate a soil 2 feet deep or one 6 feet deep. A similar condition exists when the texture of the surface soil is described as variable. When no reference is made to drainage or erosion, both are assumed to be satisfactory, whereas in some specific instance they may not be. It must be fully recognized that whenever a more accurate de- scription of the soil is available, either by more careful field examination or otherwise, the rating should be changed to conform with the more accurate information. Soil Types and Phases. — The term "soil type" as used in the soil-sur- 10 University of California — Experiment Station vey reports implies a soil which throughout the full extent of its occur- rence has relatively uniform texture of the surface soil and relatively uniform profile characteristics. It is the unit of soil mapping. The name of the soil type is a combination of the series name and the textural grade designation, as for example, Hanf ord sandy loam. The term "phase" is a subdivision of the soil type covering departures from the typical characteristics which are insufficient to merit establish- ment of separate types. Actually the term "phase" has been rather loosely used and may include : 1. Minor differences in texture, drainage, or some other features which are not fundamental but which are recognizable variations from the typical. 2. The occurrence of rock outcrop, substratum, overwash, or some other important occurrence which is not typical. 3. Soils that have recognized fundamental differences but are so inex- tensive in the area being surveyed that the necessary mechanics of sepa- rate description is not justified. In rating phases, the true condition should govern the values given rather than adherence to any prescribed classification by series names. Grades. — The term "grade" as used in this paper is an arbitrary grouping of soils having a specified range in index rating, as follows : Grade 1, index rating 80 to 100 : Excellent soils — above the average in all respects; suitable for a wide range of crops, including alfalfa, truck and field crops, orchards, vineyards ; capable of intensive develop- ment under irrigation. Grade 2, index rating 60 to 79 : Good soils — usually suitable for most crops of the region, although not quite so desirable nor of so high gen- eral value as the soils of grade 1 because of heavier-textured or lighter- textured types, heavier-textured subsoils, slight accumulations of alkali, etc. ; capable of development under irrigation. Grade 3, index rating 40 to 59 : Fair soils — will produce many crops but limited in their use and productivity by extremes of texture, heavy- textured subsoils, drainage, hardpan, erosion, bedrock, alkali in moder- ate amount, or other soil factors. Soils in this grade may give good or even excellent results with certain specialized crops or where climatic conditions are peculiarly favorable, but they do not have the range in suitability of soils in grades 1 and 2. Grade 4, index rating 20 to 39 : Poor soils — soils suitable for a few crops and these often of poor quality. They have a very narrow range in agricultural possibilities because of heavy texture, alkali, poor drain- age, infertility, hardpan or bedrock at relatively shallow depths, or Bul, 599] j± Rating op California Soils 11 other adverse soil conditions. Some soils in this grade may be improved by artificial means such as drainage and alkali reclamation. Grade 5, index rating 10 to 19 : Very poor soils — soils of very limited use except for poor pasture, because of extremely adverse conditions such as alkali, shallowness, stoniness, roughness, etc. This grade of soil is essentially nonarable. Grade 6, index rating less than 10 : Nonagricultural areas — includes such areas as are mapped in the soil survey as rough mountainous land, rough stony land, scabland, riverwash, tidal marsh, etc. Some workers in land utilization and land evaluation in other states have divided their soils into ten grades, but for California conditions five grades for agricultural land and one grade for nonagricultural material appear to be sufficient. Arrangement of Sections. — In the following pages the soil rating has been determined for each of 59 California soil-survey areas. A section is devoted to each area and they are arranged alphabetically by area name. (The areas may be located by number in the table of contents and on fig. 1, page 4.) Each section contains a brief description of the area, a listing of the major soil series by groups, the principal crops of the area, and, where the data are available, the number of acres in each of the first three grades. These descriptions are accompanied by tables showing the soil type (in the order in which they are described in the soil-survey report) ; soil group ; A, B, and C factor values ; index rating and grade of each soil type. In the Remarks columns of the tables, the reader's attention is called to pertinent facts regarding the soil which have either been used in the determination of the rating values or should be considered by anyone applying the rating to a particular tract of land. The tables and descriptions contained in this bulletin are designed particularly for use in connection with corresponding soil surveys. Since many of the latter are out of print or otherwise unavailable for general use maps have been prepared showing the location of the various grades of soil. These maps, on a much reduced scale (4 miles to the inch) and considerably abbreviated and simplified, appear in a separate cover as a part of this report. The 59 areas covered by this bulletin have been grouped into four maps and reference is made in the text to the particu- lar map which includes the area in mind. Attention should be called to the fact that because of the small scale used the accompanying maps do not show the grades of soil with the same degree of accuracy or detail that is contained in the tables or as might be obtained by applying the data to the soil maps which accom- pany the soil survey reports. 12 University of California — Experiment Station TABLE 5 Alturas Area: Rating of Soils in Accordance with the Storie Index Soil type Soil group Factors, per cent Index per cent Grade Remarks A B C VI VI VI VI VI VI V V V V VI VI V V V V V V V V II II I I V V V II II II II II II II III I 50 40 40 20 70 25 30 40 30 20 20 20 30 30 30 60 50 50 35 35 £0 80 95 95 30 30 30 80 80 80 80 80 80 90 80 95 100 60 60 60 70 35 95 90 65 55 100 100 85 55 50 50 85 55 50 35 85 70 85 70 90 90 50 100 100 85 85 100 70 100 55 80 100 100 50 75 100 100 100 90 100 100 90 90 75 80 100 100 100 100 100 100 90 80 80 80 40 40 40 30 10 30 10 60 60 100 100 100 50 24 12 9 49 9 29 32 20 11 18 18 19 13 15 30 43 28 18 12 61 45 65 53 11 11 6 24 8 20 7 48 34 90 44 76 3 4 5 6 3 6 4 4 4 5 5 5 5 5 5 4 3 4 5 5 2 3 2 3 5 5 6 4 6 4 6 3 4 3 2 2 to 3 ft. deep; rolling to hilly 2 ft. deep; stony and rough Gleason stony clay loam, steep Gleason stony clay loam, scab- Less than 1 ft. deep; very stony 40 to 50 in. deep About 1 ft. deep; intractable clay Bieber sandy loam Bieber sandy loam, calcareous- Contains heavy-textured areas; hilly Shallow ; gravelly Bieber gravelly sandy loam Shallow; rolling; low in humus Pentz loam, light-colored Shallow; often stony; infertile Gould clay loam, gravelly Gould clay, deep phase Antelope clay loam, gravelly Low water-holding capacity Clay Antelope clay loam, heavy- Friable; fertile; usually slightly alkaline Canby silty clay loam, non- Shallow; alkali Canby silty clay loam, heavy- Shallow; heavy ; alkali Lahontan fine sandy loam Lahontan fine sandy loam (A) Lahontan fine sandy loam, Moderate alkali Strong alkali Clay loam ; contains moderate Lahontan fine sandy loam, heavy-textured phase (A) Lahontan fine sandy loam, alkali Strong alkali Friable subsoil ; alkaline Lahontan fine sandy loam, Gravelly ; alkaline Friable; fertile; poor drainage Standish gravelly clay loam Surprise gravelly sandy loam Leachy Deep ; friable ; low gravel content Bul, 599] A Rating of California Soils TABLE 5 — Alturas Area — (Concluded) 13 Soil type Soil group Factors, pei cent Index per cent Grade Remarks A B C Surprise gravelly sandy loam, coarse-textured phase VII VII 95 95 95 95 95 95 95 95 95 95 95 100 100 100 100 100 15 65 65 65 80 100 100 100 100 100 85 100 90 100 50 85 100 80 20 70 100 100 70 100 80 20 100 75 90 60 90 90 14 49 12 43 76 95 67 95 76 19 81 75 81 60 45 77 60 1 1 5 3 5 3 2 1 2 1 2 5 1 2 1 2 3 2 2 6 6 Surprise gravelly sandy loam, calcareous-subsoil phase Surprise gravelly sandy loam, calcareous-subsoil phase (A) Surprise gravelly sandy loam, shallow phase Deep; friable; slight alkali Strong alkali Surprise gravelly sandy loam, dark-colored phase stratum Surprise fine sandy loam Surprise fine sandy loam, shal- Surprise fine sandy loam , dark- colored phase to 50 in. Deep and friable Surprise fine sandy loam, cal- careous-subsoil phase Deep; friable; slight alkali Surprise fine sandy loam, cal- careous-subsoil phase (A) Strong alkali Excellent soil Pit finesandy loam High in humus; poorly drained Heavy; poorly drained Pit clay, light-textured phase.. Silty clay loam to clay; poorly drained Organic soil ; poorly drained Mountainous Alkali lake beds 1. ALTURAS AREA The Alturas area is located in the extreme northeastern part of Cali- fornia. It occupies the greater part of central and eastern Modoc County, and a small portion of northeastern Lassen County. The area includes the upper Pitt River and tributary drainage, and Surprise Valley. The region lies at an elevation of between 4,000 and 5,000 feet and is char- acterized by cold winters and hot dry summers. These conditions limit the agriculture to stock raising and related types of farming. The soils of this area occupy mountainous areas, steep to gently slop- ing alluvial fans of varying age and development, and recent alluvial and lacustrine deposits. The natter areas of alluvial soils and the lacus- trine deposits are frequently poorly drained and may contain consid- erable alkali. Soils of the Gleason, Lassen, and Pentz series are developed on bed- 14 University of California — Experiment Station rock (group VI) and are often stony and shallow. They are used largely for grazing. The soils of the Bieber, Gould, Antelope, and Canby series are devel- oped on a consolidated substratum of clay (group V) and are generally of low agricultural value. Soils of the Hovey, Lahontan, Modoc, and Standish are slightly aged (group II) , while those of the Carson, Surprise and Pit series are recent (group I). The soils of both groups are made up of alluvial material having a topography generally favorable for agriculture, but often being badly waterlogged or highly alkaline. Water for irrigation is generally available for these soils. The soils of the Surprise series are extensively used for alfalfa and alfalfa seed, and those of the Pitt series for general crops. About 1,057 square miles of territory was covered by this survey, of which less than 10 per cent is irrigated. A large proportion of the area is not suited for cultivation because of rough and stony conditions or because of the high alkali content. Strong concentration of alkali is indicated by the symbol A. Table 5 shows the soil group, index rating, and grade for each soil type as described in the Soil Survey of the Alturas Area, 7 together with brief remarks on modifying conditions. The location of the various grades of soil in the Alturas area may be found in area 1 on map 1. 7 Carpenter, E. J., and R. Earl Storie. Soil survey of the Alturas area, California. U. S. Dept. Agr. Bur. Chem. and Soils. (In press.) Bul, 599] A Rating of California Soils 15 TABLE 6 Anaheim Area : Eating of Soils in Accordance with the Storie Index Soil type Soil group Factors, per cent Index per cent Grade Remarks A B c Altamont fine sandy loam Altamont loam VI VI VI VI VI VI VI II II II III II II II III II III III III I I I I I I I I I I I I I I I I I I I I 50 50 50 50 50 50 70 85 85 85 50 85 85 85 50 85 80 80 70 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 80 90 60 70 70 60 95 100 95 i9b 80 100 100 85 85 70 70 60 60 50 90 90 90 100 100 100 .100 100 100 100 100 100 100 100 100 85 85 90 100 100 100 100 100 100 100 90 90 100 90 100 90 100 100 100 90 100 90 80 90 100 80 40 100 75 30 100 75 30 100 75 30 100 75 20 100 80 45 50 40 45 30 35 49 51 73 77 48 77 68 77 50 72 68 50 49 54 48 45 90 72 36 100 75 30 100 75 30 100 75 30 100 75 20 85 68 3 3 3 3 4 4 3 3 2 2 3 2 2 2 3 2 2 3 3 3 3 3 2 2 2 to 5 ft. deep, av. 2y 2 ft.; infer- tile; texture variable Altamont loam, gravelly phase variable 2 to 5 ft. deep; av. 2}^ ft. 2 to 5 ft. deep, av. 2]/% ft. ; texture and topography variable Altamont clay elevation Av. depth V/i ft. cated Compact subsoil; texture some- what variable Ramona sandy loam, reddish- Ramona sandy loam, heavier- mona Texture variable Loam with some gravel Includes some variations ; erosive Ramona loam, heavier-subsoil Heavy subsoil; not typical Ra- mona Wide variation in color and some Montezuma clay loam adobe... in texture Somewhat variable Texture and topography variable Recent river deposits of variable texture Hanford sand, coarse phase Gravelly Surface and subsoil texture var- iable Slight alkali Alkali Hanford fine sandy loam (S).... Hanford fine sandy loam (A).... Slight alkali Alkali Texture variable Slight alkali Alkali Texture and depth variable Slight alkali Alkali Texture variable Yolo loam (S) Slight alkali Alkali Slight alkali 16 University of California — Experiment Station TABLE 6 — Anaheim Area — (Concluded) Soil type Soil group Factors, per cent Index per cent Grade Remarks Yolo clay loam (A) Yolo clay adobe Yolo clay adobe (S) Yolo clay adobe (A) Dublin clay adobe Dublin clay adobe (S).. Dublin clay adobe (A). Chino silt loam Chino silt loam (S) Chino silt loam (A) Chino silty clay loam. Chino silty clay loam (S).. Chino silty clay loam (A). Chino clay loam Chino clay loam (S). Chino clay loam (A). Chino silty clay Chino silty clay (S).... Chino silty clay (A) Chino silty clay, heavy phase Muck and peat Tidal marsh Coastal beach and dunesand.. Riverwash Rough broken and stony land I I I VII VII VII VII 100 100 100 100 100 100 100 95 95 95 95 95 95 95 95 95 95 95 95 95 60 100 100 100 30 100 76 77 Alkali Slight alkali Alkali Slight alkali Alkali Drainage generally somewhat restricted Slight alkali Alkali Drainage generally somewhat restricted Slight alkali Alkali Variable; includes soils of Han- ford and Dublin Slight alkali ; drainage somewhat poor Alkali Drainage restricted Slight alkali ; drainage some- times poor Alkali Drainage usually poor Drainage usually poor Nonagricultural Nonagricultural Nonagricultural Nonarable 2. ANAHEIM AREA The Anaheim area is located along the southern coast of California and covers the major portion of Orange County. A considerable portion of the area lies at an elevation of less than 100 feet and most of it is below 500 feet. The climate is characterized by mild temperatures throughout the year, with most of the rain falling during the winter. Included within the area are the recent delta-fan deposits of the Santa Ana River and minor streams giving rise to soils of the Hanford, Yolo, Dublin, and Chino series (group I) ; the somewhat more mature second- ary soils of the Ramona, Montezuma, and Antioch series (groups II and III), and the primary soils of the Altamont and Diablo series (group VI) . Portions of the lower fan deposits are subject to poor drainage and slight to moderate accumulations of alkali. Some of these areas have been drained. A very large proportion of the tillable lands of the area are in culti- Bul, 599] a Rating of California Soils 17 vation and the yields are relatively high. Walnuts, citrus fruits, alfalfa, sugar beets, beans, and a wide variety of truck and general farm crops are grown on the alluvial soils of groups I and II ; while grain, grain hay, beets, and beans are the principal crops on the older alluvial soils of group III. The primary soils of group VI are largely devoted to pas- ture and grain, but the more favorably located areas, where water is available, are used for citrus and other fruits. Climate and the availabil- ity of irrigation water may be the governing factors in the location of citrus and other specialized crops. Out of a total of 317,440 acres included in this survey, 139,776 acres are rated as grade-1 soils, and 72,832 acres as grade-2 soils. Table 6 shows the soil group, index rating, and grade for each soil type as found in the Soil Survey of the Anaheim Area. 8 For those soils which are subject to alkali accumulations, a separate rating has been given. The symbol A indicates a moderate to strong alkali content and the symbol S a slight concentration. The location of the various grades of soil in the Anaheim area may be found in area 2 on map 4. s Eckman, E. C, et al. Soil survey of the Anaheim area, California. U. S. Dept. Agr. Bur. Soils, Field Oper. 1916:1-79. 1919. 18 University of California — Experiment Station TABLE 7 Auburn Area : Eating of Soils in Accordance with the Storie Index Soil type Soil group Factors, per cent Index per cent Grade Remarks Aiken clay loam Aiken clay loam, shallow phase Aiken clay loam, yellow-sub soil phase Aiken stony clay loam Holland sandy loam Holland sandy loam, rock- outcrop phase Sierra sandy loam Columbia fine sandy loam Columbia fine sandy loam, shallow phase Columbia fine sandy loam, coarse-textured phase Columbia silt loam Sites stony loam Siskiyou coarse sandy loam Whitney fine sandy loam Madera loam Rocklyn fine sandy loam Rocklyn fine sandy loam, brown phase Rocklyn fine sandy loam, gravelly phase San Joaquin fine sandy loam... San Joaquin gravelly loam San Joaquin loam Corning gravelly loam Kimball loam Placentia sandy loam Placentia sandy loam, brown phase Honcut clay loam Honcut clay loam, yellow- subsoil phase Hanford sandy loam Alamo clay Hovey clay I I VI VI VI IV IV IV IV IV IV IV III III III II I III I IV 50 100 100 100 100 50 50 40 50 20 30 20 25 25 25 50 95 100 30 80 85 85 85 60 95 70 95 100 100 40 100 70 90 100 100 100 100 70 100 70 100 70 100 95 95 100 100 80 100 100 100 100 80 100 80 100 100 100 100 100 100 100 100 100 100 90 100 100 50 100 100 30 to 70 in. deep Less than 30 in. deep 12 to 24 in. deep ; low in humus Shallow ; rolling to steep topog- raphy About 30 in. deep About 30 in. deep; rocks inter- fere with cultivation 30 in. deep Overflow; texture and stratifica- tion variable Heavy subsoil; overwash on Kimball soil Sand or coarse sand Water table variable 30 to 40 in. deep; topography variable 36 in. deep; low in humus 24 in. deep; poorly drained in places 40 in. deep; considerable varia- tion as mapped 24 in. deep; hardpan on consoli- dated substratum Slightly better soil than fine sandy loam Shallow; consolidated sub- stratum Av. 30 in. deep; hummocky Under 30 in. deep ; hummocky Under 30 in. deep; hummocky Shallow; many areas have been placer-mined Low rolling hills Deep; better than typical Occurs in narrow strips Drainage poor; not typical of Drainage poor; variable Shallow; similar to San Joaquin soils May be shallow Bul. 599] A Rating of California Soils TABLE 7 — Auburn Area — (Concluded) 19 Soil type Soil group Factors, per cent Index per cent Grade Remarks A B C V VII VII VII VII 20 70 100 14 10 3 1 3 5 5 6 6 6 Nonarable Nonarable Nonagricultural Nonagricultural 3. AUBURN AREA The Auburn area covers the major portion of the agricultural lands of Placer County. Included in this area are soils occupying mountainous regions, foothills, and a flat valley floor. Elevations range from less than 100 to more than 4,000 feet. The winters are cool and rainy, and the summers are hot and dry. The amount of precipitation increases with elevation from about 20 to 50 inches. In the valley region are found the semimature secondary soils (group III) of the Corning, Kimball, and Placentia series and the mature hard- pan soils (group IV) of the Madera, Rocklyn, and San Joaquin series. The group I, or recent alluvial soils, are of very limited extent, but in- clude small areas of Columbia, Honcut, and Hanford. The secondary soils are devoted largely to grain and pasture. The lower foothill sec- tions are occupied by primary soils (group VI) of the Aiken, Holland, Sierra, Sites, Siskiyou, and Whitney series, and are devoted to grain, pasture, grapes, and deciduous fruits. The soils of the Holland series are extensively planted to plums, pears, peaches, and cherries. The higher foothills and mountainous areas are primary soils, mostly of the Aiken series, which at present are mainly forested. Table 7 gives the soil group, index rating, and grade for each soil type as described in the Soil Survey of the Auburn Area, 9 with brief refer- ence to some of the more important soil features which may influence the index rating. Alkali is not a factor of importance in this area, al- though locally poor or restricted drainage may be present. There are 391,040 acres included in this survey, of which nearly one- third is nonarable. Only 6,336 acres have been rated as grade-1 soils and 10,880 acres as grade-2. Geographic location, air drainage, and availabil- ity of irrigation water have governed the agricultural development in this area, resulting in an extensive deciduous-fruit industry on soils of medium index rating. The soil grades in the Auburn area may be found in area 3 on map 1. 9 Cosby, Stanley W., E. B. Watson, and W. G. Harper. Soil survey of Auburn area, California. U. S. Dept. Agr. Bur. Chem. and Soils, Ser. 1924, Eept. 15:1-38, 1928. 20 University of California — Experiment Station TABLE 8 Barstow Area : Eating of Soils in Accordance with the Storie Index Soil type Soil group Factors, per cent Index per cent Grade Remarks. A B C 1 I I I I I I I II II II II II II II II II I III III III III III III III III III III IV III III III III IV IV and II VII VII VII VII VII 100 100 100 100 100 100 100 100 100 100 90 90 90 90 90 90 90 90 90 95 80 60 60 80 60 60 60 60 60 60 50 60 60 60 60 40 65 65 65 65 100 100 100 80 80 100 65 40 70 100 100 100 90 90 90 70 60 90 90 80 90 90 90 90 90 90 90 90 90 90 90 65 90 80 40 30 75 55 20 90 80 75 90 80 90 90 40 20 70 50 20 95 40 90 80 95 100 80 60 90 60 20 25 100 80 60 20 60 59 52 26 20 75 55 20 72 64 75 53 29 57 81 36 18 57 41 16 63 19 49 43 61 54 43 32 49 32 11 11 54 43 32 11 16 16 53 5 5 5 1 2 3 3 4 4 2 3 4 2 2 2 3 4 3 1 4 5 3 3 5 2 5 3 3 2 3 3 4 3 4 5 5 3 3 4 5 5 5 3 6 6 6 6 6 Cajon finesand, dune phase ... Cajon finesand, dune phase (S) Cajon fine sandy loam (S) Cajon fine sandy loam (M) Caj on fine sandy loam (A) Sand dunes ; rough ; leachy Slight alkali Slight alkali; deep; friable Moderate alkali Strong alkali Deep; friable; drainage restricted Slight alkali Foster loamy sand (S) Foster fine sandy loam (S) Daggett gravelly sandy loam.. Daggett gravelly sandy loam, Slight alkali Slightly eroded Eroded and stony Rosamond fine sandy loam (S) Rosamond fine sandy loam (M) Rosamond fine sandy loam (A) Rosamond silty clay loam (S) Rosamond silty clay loam (M) Rosamond silty clay loam (A) Hesperia coarse sandy loam Slight alkali Moderate alkali Strong alkali Slight alkali Moderate alkali Strong alkali Texture variable; low in humus High stony fans ; eroded Adelanto sandy loam (S) Adelanto sandy loam, deep phase Slight alkali Texture variable Yermo sandy clay loam (S) Yermo sandy clay loam (M) Yermo sandy clay loam, dune phase Slight alkali Moderate alkali Rough topography Yermo sandy clay loam, dune phase (S) Alkali-spotted Yermo sandy clay loam, dune phase (A) Strong alkali Yermo sandy clay loam, Soft hardpan; strong alkali; Mojave sandy loam drainage poor Variable texture Slight alkali Mojave sandy loam (M) Moderate alkali Mojave sandy loam (A) Strong alkali Barstow gravelly sandy loam Barstow and Daggett grav- elly sandy loam, undiffer-- entiated Riverwash Shallow ; hardpan ; rough ; eroded Eroded Eroded Nonagricultural Playa deposits Nonagricultural Dunesand Nonagricultural Rough stony land Nonarable Rough broken land Nonarable Bul. 599] j± Rating of California Soils 21 4. BARSTOW AREA The Barstow area is located in central and west-central San Bernardino County, and includes the lands bordering the Mojave River from about Oro Grande to Troy. This is a desert region of cool dry winters and long hot summers. Elevations in the area are from 2,000 to 3,000 feet. The soils are all secondary, but range from recent deposits (group I) such as those of the Cajon, Foster, and Hesperia series, through those having more fully developed profiles, such as the Daggett and Rosamond (group II) and Troy, Adelanto, Yermo, and Mojave (group III), to those having well-developed hardpans (group IV) such as found in the Barstow series. Many of these soils are poorly drained and contain con- siderable amounts of alkali. Alfalfa is practically the only crop grown at the present time, and no crops are produced without irrigation. Table 8 gives the soil group, the index rating, and grade of each soil type described in the Soil Survey of the Barstow Area, 10 with brief re- marks on alkali conditions and other factors influencing their value and rating. The symbol S indicates slight alkali; M, moderate alkali; and A, strong alkali accumulations. Approximately 169,600 acres are cov- ered by this survey. None of the soils of this area are placed in grade 1 (index rating over 80) ; only 12,160 acres are in grade 2 (rating 60 to 79) ; and 76,560 acres in grade 3 (rating 40 to 59). The location of the various grades of soil in the Barstow area may be found in area 4 on map 4. io Storie, E. Earl. Soil survey of Barstow area, California. U. S. Dept. Agr. Bur. Chem. and Soils. (In press.) 22 University of California — Experiment Station TABLE 9 Big Valley Area : Eating of Soils in Accordance with the Storie Index Soil type Soil group Factors, per cent Index per cent Grade Remarks A B C VI VI V V V V V V II II II II II II I I I I I I II II II II II II 40 30 30 20 30 30 40 20 80 80 80 80 80 80 95 100 100 100 100 100 90 90 90 90 90 90 65 65 95 65 70 65 100 100 100 100 100 100 100 100 100 100 100 70 60 60 65 65 100 100 100 85 100 80 80 80 80 100 100 100 50 20 10 50 20 10 80 30 10 100 60 60 100 60 60 80 60 70 26 16 23 10 17 20 40 20 40 16 8 40 16 8 76 30 10 70 36 36 59 35 54 72 54 54 4 5 4 5 5 4 3 4 3 5 6 3 5 6 2 4 5 2 4 4 3 4 3 2 3 3 Av. depth 2 ft. ; depth and Underwood stony sandy loam stoniness variable Shallow soils V/i ft.; as mapped includes areas of nontypical soils ; erosion active Gould sandy loam, gravelly times hummocky or stony 10 to 15 in. to substratum; may be hummocky Bieber gravelly sandy loam flow Drainage usually poor Bieber fine sandy loam, heavy Substratum usually at 6 to 18 in. Modoc fine sandy loam (S) Modoc fine sandy loam (A) Modoc fine sandy loam, gray stratum; texture variable Spotted alkali Alkali Modoc fine sandy loam, gray stratum; some areas subject to overflow Modoc fine sandy loam, gray Alkali Vina loam (S) substratum; all of the Vina soils in this area have consoli- dated substratum often result- ing in poor drainage and alkali; some areas also subject to overflow Alkali Vina clay adobe Vina clay adobe, shallow phase Buntingville fine sand Vina loam Shallow Buntingville fine sand, shal- Buntingville fine sandy loam.. Buntingville very fine sandy Subject to overflow Buntingville very fine sandy subsratum iable Bul. 599] a Rating of California Soils 23 TABLE 9 — Big Valley Area — (Concluded) Soil type Soil group Factors, per cent Index per cent Grade Remarks A B C I I I I VII VII 100 100 100 85 85 60 60 40 60 51 34 36 40 3 5 3 4 4 3 6 6 Pit clay loam, shallow phase... areas of Buntingville and of hardpan Shallow on substratum; subject to overflow overflow Drainage poor; includes admix- tures of mineral soils and some peats 5. BIG VALLEY AREA The Big Valley area is located in northwestern Lassen and southwestern Modoc counties. This is an intermountain valley in the lava region and lies at an elevation of 4,100 to 4,300 feet. It is a region having dry, cold winters and dry, hot summers. The primary soils (group VI) consist of the Aiken and Underwood series, and are usually shallow and stony. The soils of the Gould and Bieber series (group V) are shallow and rest on a substratum of dense, hard material. The Modoc and Buntingville series (group II) are sec- ondary soils with a slightly developed profile, while the Vina and Pit (group I) consist of more recently deposited material. Poor drain- age and alkali occur in places, and as a whole the soils are of rather low value. Stock raising is the principal industry, with alfalfa and grain on the better soils. Table 9 gives the soil group, index rating, and grade for each type of soil described in the Soil Survey of the Big Valley Area, 11 with brief remarks on the variations and modifying factors. In this area the sym- bol S signifies spotted with alkali and the symbol A moderate to strong concentrations of alkali. The area covers 156,800 acres, with no soils having a rating of over 80. Only 12,160 acres have a rating over 60, and 32,448 acres are rated between 40 and 60. The location of the various grades of soil in the Big Valley area may be found in area 5 on map 1. ii Watson, E. B., and Stanley W. Cosby. Soil Survey of the Big Valley area, Cali- fornia. IT. S. Dept. Agr. Bur. Soils, Field Oper. 1920:1005-32. 1924. 24 University of California — Experiment Station TABLE 10 Bishop Area : Eating of Soils in Accordance with the Storie Index Soil type Soil group Factors, per cent Index per Grade Remarks Cajon sandy loam Caj on sandy loam, stony phasi Cajon gravelly sandy loam Cajon finesandy loam Cajon fine sandy loam (A) Cajon finesandy loam (S) Cajon stony sand Cajon stony sand, boulder phase Panoche fine sandy loam Panoche finesandy loam (A)... Panoche fine sandy loam (S) Panoche fine sandy loam, gravelly phase Panoche finesandy loam, stony phase Panoche loam Panoche loam (A) Panoche loam (S) Foster sandy loam Foster sandy loam, stony phase Foster sandy loam, gravelly phase(A) Foster sandy loam, gravelly phase(S) Foster finesandy loam Foster fine sandy loam (A) Foster fine sandy loam ( S) Bishop fine sandy loam Bishop fine sandy loam (A) Bishop finesandy loam (S) Bishop fine sandy loam, grav elly-subsoil phase Bishop fine sandy loam, grav elly-subsoil phase (A) Bishop fine sandy loam, grav elly-subsoil phase (S) Bishop sandy loam Bishop sandy loam (A) Bishop sandy loam, gravelly subsoil phase Bishop sandy loam, gravelly subsoil phase (A) Stacy sand 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 95 65 65 100 100 100 25 10 100 100 100 70 50 100 100 100 95 65 95 95 100 100 100 100 100 100 100 100 100 95 95 95 95 60 58 10 90 90 90 58 10 100 90 50 10 80 40 10 50 25 8 40 20 4S Low in humus; may have grav- elly subsoil Low in humus; stonier than typical Porous and leachy , having gravel throughout profile Surface texture varies; drainage often deficient Moderate alkali Strong alkali Porous and leachy; many large stones Excessively stony Low in humus; hummocky in places Moderate alkali Strong alkali Gravelly and leachy Stony and leachy Friable; low in humus Moderate alkali Strong alkali High in humus Slightly eroded Moderate alkali Strong alkali Drainage usually poor Moderate alkali Strong alkali Drainage characteristically poor Moderate alkali Strong alkali Gravelly subsoil; usually alka- line Moderate alkali Strong alkali Drainage poor; texture variable Moderate alkali Poor drainage Moderate alkali Fertility low; gravel content Bul. 599] A Rating of California Soils TABLE 10 — Bishop Area — (Concluded) 25 Soil type Soil group Factors, per cent Index per Grade Remarks Stacy sand (A) Johnstonvillesand Mono gravelly sand Preston sand Preston sand, dune phase Elna fine sand (A) Elna fine sand (S) Elna sandy loam (A) Elna sandy loam (S) Elna sandy loam, brown phase (A) Elna sandy loam, brown phase (S) Elna fine sandy loam (A) Elna fine sandy loam (S) Elna fine sandy loam, brown phase (A) Elna fine sandy loam, brown phase(S) Lynndylsand Lynndyl sand, poorly drained phase Lynndyl sand, gravelly phase Gazelle sand Lahontan loamy fine sand (A) Lahontan loamy fine sand (S) . Lahontan fine sandy loam (A) Lahontan fine sandy loam (S) Lahontan silt loam (A) Lahontan silt loam (S) Peat Scabland Rough broken land Rough stony land I IV IV I I IV IV IV IV IV IV IV IV IV IV II II II IV II II II II II II I VII VII VII 100 30 20 100 100 40 40 40 40 40 40 40 40 40 40 85 85 85 60 85 85 85 85 85 85 60 25 60 30 65 65 95 95 95 95 100 100 100 100 60 60 20 60 90 90 100 100 100 100 40 100 80 60 40 60 10 60 10 60 10 60 10 60 10 80 25 80 40 40 10 40 10 40 10 Moderate alkali Hardpan soil Hardpan 12 to 18 in. ; eroded Hummocky Hummocky Moderate alkali; texture varies Strong alkali Moderate alkali Strong alkali Moderate alkali Strong alkali Moderate alkali Strong alkali Moderate alkali Strong alkali Low in humus; hummocky Poorly drained Very leachy ; low in humus Poor drainage and alkali Moderate alkali ; low in humus Strong alkali Moderate alkali; hummocky Strong alkali Moderate alkali Strong alkali Drainage usually poor Nonarable Nonarable Nonarable 6. BISHOP AREA The Bishop area occupies the northern portion of Owens Valley in Inyo County. It extends from the northern end of Long Valley at the Mono- Inyo line southward to the Narrows at Poverty Hills. The area lies at an elevation of between 3,800 feet and 4,900 feet. On both the east and west, high mountains rise abruptly from the valley floor. This area has an arid climate and is characterized by cold, dry winters when most of the moisture comes as snow, and hot, dry summers with occasional thunder showers. The soils of the Bishop area are all secondary ; some of them, however, as, for example, the Johnston ville, Mono, Elna, and Gazelle series (group IV) have weathered for sufficient time to have developed hardpans. The soils of the Lynndyl and Lahontan series (group II) have less mature 26 University of California — Experiment Station profiles, the former having developed from old lake-bed sediments. The soils of the Cajon, Panoche, Foster, Bishop, Stacy, and Preston series (group I) are recent deposits. Many of the soils of this area are poorly drained and contain alkali. Prior to the extensive acquisition of water rights in the Owens Valley by the City of Los Angeles, the better and more favorably located areas of Foster, Cajon, and Panoche soils were devoted to alfalfa and decidu- ous fruits. Freedom from frost, as well as water supply, governed the location of fruit plantings. Native and cultivated hay crops with their accompanying dairy and livestock farms occupied much of the remain- ing land where alkali was not a limiting factor. The shallow and poorer soils of the area were devoted to salt grass and other native pasture grasses for cattle, sheep, and horses. Since the available supply of irri- gation water has become limited, most of the orchards and many of the alfalfa fields have been abandoned. Agriculture is largely limited to the growing of native wild hay, and the feeding of beef cattle and sheep. The removal of water from the valley has so lowered the water table that even the native vegetation has been greatly reduced. In the alkali classification used in this survey, the symbol S indicates a strong concentration, and the symbol A, a moderate concentration. Table 10 shows the soil group, index rating, and grade for each soil type found in the Soil Survey of the Bishop Area. 12 There are 190,080 acres included in this survey. The location of the various grades of soil in the Bishop area may be found in area 6 on map 1. 12 Watson, E. B., and R. Earl Storie. Soil survey of the Bishop area, California. U. S. Dept. Agr. Bur. Chem. and Soils, Ser. 1924, Kept. 3:63-95. 1928. Bul. 599] A Eating of California Soils 27 TABLE 11 Brawley Area: Rating of Soils in Accordance with the Storie Index Soil type Soil group Factors, per cent B Ct Index per cent Grade Remarks Imperial very fine sandy loam Imperial loam Imperial clay loam Imperial clay loam, stratified Imperial silty clay loam Imperial silty clay Imperial silty clay, stratified... Imperial clay Imperial clay, stratified Holtville very fine sandy loam Holtvilleloam Holtville silty clay loam Holtville silty clay Holtville clay Woodrow fine sandy loam (S) Woodrow clay (S) Woodrow clay, light-textured phase (S) Tijeras gravelly sandy loam Tijeras gravelly clay Superstition gravelly coarse sand Superstition gravelly sand Superstition sand Niland gravelly sand Niland gravelly fine sand Niland gravelly fine sand, stony Niland gravelly clay loam Rositas fine sand Rositas very fine sandy loam.... Meloland fine sand Meloland fine sandy loam Meloland fine sandy loam, stratified Rough stony land Rough broken land Dunesand Riverwash VII VII VII VII 75* 75* 75* 85* 75 : ' 75* 85* 75* 85* 95 95 95 95 95 90 90 90 90 90 90 90 80 100 100 85* 85* 90 100 100 85 85 90 65 65 55 55 100 100 90 65 50 100 30 65 70 60 30 50 60 50 40 40 55 65 100 65 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 20 20 20 100 100 70 90 75 100 100 40 80 85 95 100 100 100 Heavy subsoil (should be Melo- land) Heavy subsoil (should be Melo- land) Heavy subsoil Stratified subsoil (should be Holtville) Heavy subsoil Stratified subsoil (Holtville) Very heavy Stratified subsoil (should be Holtville) Light subsoil Light subsoil Light subsoil Light subsoil; may be stratified Light subsoil; may be stratified No areas without alkali; drain- age poor No areas without alkali age poor drain- No areas without alkali; drain- age poor Very compact subsoil Very compact subsoil Coarse-textured Coarse-textured; leachy Coarse sand ; leachy Coarse to medium-textured Medium-textured Very stony Compact subsoil Light-textured, leachy, and possibly rough Light-textured surface and sub- soil Heavy subsoil Heavy subsoil Stratified subsoil (should be Holtville) Nonarable Nonarable Nonagricultural Nonagricultural * Factor A of Imperial and Meloland reduced below normal for group on account of very heavy subsoils. t On an alkali-free basis, except as noted. See table 12 for rating with alkali. 28 University of California — Experiment Station TABLE 12 Effect of Varying Degrees of Alkali on the Index Value of Soils in Brawley Area Soil type F, alkali- free, per cent M, slightly affected, per cent A, moderately affected, per cent 67 45 67 45 56 37 64 43 60 40 43 29 49 33 36 24 43 29 86 57 86 57 69 51 55 38 43 29 33 25 16 22 14 40 27 36 24 40 27 32 21 13 8 31 20 49 34 85 57 49 33 76 51 72 54 5 3 3 2 s, strongly affected, per cent Imperial very fine sandy loam Imperial loam Imperial clay loam Imperial clay loam, stratified phase. Imperial silty clay loam Imperial silty clay Imperial silty clay, stratified Imperial clay Imperial clay, stratified Holtville very fine sandy loam Holtville loam Holtville silty clay loam Holtville silty clay Holtville clay Woodrow fine sandy loam Woodrow clay Woodrow clay, light-textured phase Tijeras gravelly sandy loam Tijeras gravelly clay Superstition gravelly coarse sand Superstition gravelly sand Superstition sand Niland gravelly sand Niland gravelly fine sand Niland gravelly fine sand, stony phs Niland gravelly clay loam Rositas fine sand Rositas very fine sandy loam Meloland fine sand Meloland fine sandy loam Meloland fine sandy loam, stratified Dunesand Riverwash 4s 7. BRAWLEY AREA The Brawley area comprises the northern portion of Imperial Valley and extends from Imperial northward to Salton Sea. Imperial Valley occupies the lowest part of the desert region at the extreme southern end of the state. The climate is characterized by an almost negligible rainfall, long hot summers, and mild winters. The soils in the cultivated portion of this area are composed of strati- fied, variable-textured deposits from Colorado River sediments. Some of the deposits have been made from flowing water and others from tem- porary lakes, and have been modified to varying degrees by wind action. The texture of the soil and the sequence of stratification were used Bul. 599] a Rating of California Soils 29 largely as a basis for series separation. The most extensive soils of the area are the Imperial, Holtville, Meloland, Rositas, and Woodrow series, all in group I. Alkali and poor drainage are important considerations in this area. Surrounding these recently deposited soils and at slightly higher ele- vations is a group of older secondary soils derived from the surround- ing hills and mesas. The Superstition and Niland series are in group II, and the Tijeras series is in group V ; the latter having a compact im- pervious substratum. This survey covers 391,040 acres, of which 14,000 acres are in grade 1, and about 31,000 acres in grade 2, and about 93,000 acres in grade 3. No crops of any kind can be grown in this region without irrigation. With the exception of a comparatively small acreage of grapefruit, there are no permanent crops grown in Imperial Valley. Large acreages of alfalfa, cantaloupes, lettuce, melons, and other annual crops are rotated on the soils best suited from the standpoint of texture and alkali content. Barley, corn, flax, and to a limited extent cotton are rotated on the heavier-textured soils and some of those containing slight to mod- erate amounts of alkali. Table 11 shows the soil group, index rating, and grade for each of the soil types found in the Soil Survey of the Brawley Area. 13 This table is based on alkali-free conditions, but since alkali accumulations varying from negligible to strong are to be found on practically every soil type, table 12 has been prepared to indicate the range in index rating under these conditions. In the alkali classification used in this survey, the sym- bol M indicates slightly affected ; A, moderately affected ; and S, strongly affected soil. The location of the various grades of soil for the Brawley area may be found in area 7 and map 4. 13 Kocher, A. E., et al. Soil survey of the Brawley area, California. U. S. Dept. Agr. Bur. Soils, Field Oper. 1920:641-716. 1923. 30 University of California — Experiment Station TABLE 13 Capistrano Area : Eating of Soils in Accordance with the Storie Index Soil type Soil group Factors, pei cent Index per cent Grade A B C VI 60 95 100 57 3 VI 60 95 100 57 3 VI 50 100 100 50 3 VI 30 60 100 18 5 VI 40 85 80 27 4 VI 30 65 100 20 4 VI 30 65 100 20 4 VI 40 100 100 40 3 VI 50 50 100 25 4 VI 50 50 100 25 4 VI 40 50 80 16 5 VI 50 100 95 48 3 I 100 95 100 95 1 I 95 95 95 86 I I 100 100 90 90 1 I 100 60 80 48 3 II 85 80 90 61 2 II 90 95 100 86 1 I 95 80 100 76 2 I 95 85 100 81 1 II 95 95 100 90 1 II 95 100 100 95 1 II 95 100 100 95 1 II 95 85 100 81 1 I 100 70 100 70 2 I 100 70 90 63 2 II 95 95 100 90 1 I 95 85 70 57 3 V 20 100 90 18 5 V 40 100 90 36 4 V 25 95 90 21 4 III 40 100 100 40 3 III 40 100 100 40 3 III 40 100 90 36 4 III 40 85 95 32 4 III 50 95 100 48 3 Remarks Fallbrook sandy loam Vista sandy loam Escondido very fine sandy loam Konokti gravelly loam Carlsbad loamy fine sand Ysidora gravelly sandy loam... Ysidora gravelly sandy loam, dark-colored phase Altamont fine sandy loam Altamontclay Diablo clay adobe Diablo clay adobe, steep phase Linneloam Hanford sandy loam Laguna sandy loam Foster very fine sandy loam Cajonsand Elkhorn loamy sand Ramona sandy loam Botella loamy sand Botella loamy sand, heavy- textured phase Salinas sandy loam Salinas fine sandy loam Salinas fine sandy loam, light- colored phase Salinas fine sandy loam, heavy-textured phase Farwell gravelly sandy loam... Farwell gravelly sandy loam, gray phase Commatti sandy loam Clear Lake sandy clay loam Las Flores fine sandy loam Las Flores fine sandy loam, friable-subsoil phase Tierra sandy loam Aliso fine sandy loam Huerhuero fine sandy loam Stockpen fine sandy loam Stockpen fine sandy loam, heavy-textured phase Merriam sandy loam 30 to 50 in. deep ; some stony areas 30 to 60 in. deep; hilly to rolling 20 to 44 in. deep Shallow; high stone content 20 to 40 in. deep ; eroded ; acid 18 to 30 in. deep ; subsoil variable; gravelly 18 to 26 in. deep Depth and texture somewhat variable 30 to 40 in. deep 30 to 40 in. deep; high in humus Steep slopes 32 to 44 in. deep; slightly eroded; hilly Texture somewhat variable; may contain alkali Subject to occasional overflow May contain alkali; texture somewhat variable Subject to overflow; gravelly seams in subsoil Somewhat infertile May contain stony areas Clay loam Texture varies somewhat Clay loam Slightly less fertile than typical Texture variable; drainage fair Shallow; overlaying heavy clay; infertile Deeper than typical for series Heavy clay subsoils; shallow; eroded Surface texture variable Subsoils approach hardpan Low in humus Clay loam surface texture Bul. 599] A Rating of California Soils TABLE 13 — Capistrano Area — (Concluded) 31 Soil type Soil group Factors, per cent Index per cent Grade Remarks A B C III VII VII VII VII VII 10 50 100 35 5 5 2 1 1 4 6 6 6 6 6 Rough mountain land Coastal beach and dunesand.... tent ; nonagricultural Nonagricultural 8. CAPISTRANO AREA The Capistrano area is located in northwestern San Diego County and southwestern Orange County, adjacent to the coast. There are no ex- tremes in climate, both summer and winter being mild. The rain comes mostly in midwinter. Elevations up to about 2,000 feet are found in some of the higher peaks of the area. Soils of the Fallbrook, Vista, Escondido, Konokti, Carlsbad, Ysidora, Altamont, Diablo, and Linne series are group-VI soils, weathered in place from the underlying bedrock. The deeper soils of this group are used for citrus, avocados, grapes, and other crops, where favorably lo- cated and where water is available. Shallow depth and lack of water for irrigation have restricted the use of many of these soils. The soils of the Tierra and Las Flores series (group V) and Aliso, Huerhuero, Stockpen, Merriam, and Montezuma series (group III) are maturely weathered secondary soils with heavy clay subsoils or sub- stratum, and are of limited agricultural value. The soils of the Elkhorn, Ramona, Salinas, and Commatti series (group II) and Botella, Farwell, and Clear Lake series (group I) show moderate to slight clay accumulations in the subsoil. These soils, when favorably located and supplied with irrigation water, are among the most valuable of the area. The soils of the Hanford, Laguna, Foster, and Cajon series (group I) are the most recent deposits and are frequently rather poorly drained and alkaline. Location and the availability of water have frequently been greater factors in determining the use of the soil than has the character of the soil itself. The poorer soils, however, such as those of the Tierra and Las Flores series, have not proved well suited to farming, and yields have been light. Table 13 gives the soil group, index rating, and grade of the several soil types as found in the Soil Survey of the Capistrano Area. 14 " There 14 Carpenter, E. J., and E. Earl Storie. Soil survey of the Capistrano area, Cali- fornia. U. S. Dept. Agr. Bur. Chem. and Soils, Ser. 1929, Eept. 18:1-48. 32 University of California — Experiment Station are 267,520 acres covered by this survey, 23,296 of which are in grade 1 ; 9,920 in grade 2 ; and 22,912 in grade 3. The location of the various grades of soil in the Capistrano area may be found in area 8 on map 4. Bul, 599] A Rating of California Soils 33 TABLE 14 Chico Area: Eating of Soils in Accordance with the Storie Index Soil type Soil group Factors, per cent Index per Grade Remarks Aiken clay loam Aiken clay loam, stony phase Sites fine sandy loam Mariposa stony loam Pentz clay loam Pentz clay adobe Corning gravelly sandy loam.. San Joaquin sandy loam Redding clay loam Redding clay loam, gravelly phase Tuscan stony clay loam Tuscan gravelly clay loam Anita clay loam Anita clay loam, reddish phase Anita clay adobe Anita clay adobe, overwash phase Keefers gravelly loam Keefers gravelly loam, stony phase Landlow clay loam Landlowclay Landlow clay adobe Stockton clay adobe Stockton clay adobe, brown- ish phase Stockton clay adobe, overwash phase Farwell fine sandy loam Farwellloam Farwell clay loam Farwell clay adobe Nord finesandy loam Nordloam Vina stony loam Vina fine sandy loam Vina loam Vina loam, shallow phase Vina loam, gray phase Vina clay loam Vina clay loam adobe Conejoloam Conejo clay loam Conejo clay loam, heavy- textured phase Honcut sandy loam Columbia very fine sandy loam Columbia loam Columbia loam, shallow phase VI VI VI VI VI VI III IV IV IV V V II III II II III III V V V V 80 30 40 40 40 40 40 95 95 95 95 90 90 100 100 100 100 100 100 100 100 100 100 100 100 100 100 60 80 100 100 85 60 100 100 70 100 100 100 100 85 85 100 85 95 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 80 SO 100 100 100 100 100 100 100 100 90 90 90 90 90 90 100 100 100 60 95 100 90 90 80 70 100 100 38 45 73 51 81 81 70 100 100 60 95 85 77 90 77 48 67 100 100 Deep; friable Deep ; somewhat stony 3 to 4 ft. deep; texture variable Very shallow Very shallow 12 to 24 in. deep Gravelly subsoil Less than 3 ft. to hardpan Shallow Shallow; gravelly Nonarable Nonarable Drainage poor Very shallow ; drainage poor ; nonty pical of series Drainage poor Ramada over Anita Compact stony subsoil Very stony Consolidated substratum at 2 to 3 ft. Consolidated substratum at 3 ft. Consolidated substratum at 3 ft. Consolidated substratum at 3 ft. Consolidated substratum at 3 ft. Ramada over Stockton Drainage somewhat restricted Drainage somewhat restricted Drainage somewhat restricted Drainage somewhat restricted High in lime; drainage restricted High in lime; drainage restricted Deep; friable Deep ; friable Vina over Tuscan Similar to Sutter series Drainage may be poor Drainage fair ; slightly alkaline Drainage fair Drainage fair Clay ; drainage poor Usually an overwash on Corning Deep ; friable Deep; friable Columbia over Anita or Farwell 34 University of California — Experiment Station TABLE 14 — Chico Area — (Concluded) Soil type Soil group Factors, pei •cent Index per cent Grade Remarks A B C II I VII VII VII VII 95 100 60 100 50 70 29 70 3 3 3 4 2 6 6 6 6 Drainage very poor Stratified and variable-textured Nonagricultural Nonagricultural Nonarable Rough broken and stony land Nonarable 9. CHICO AREA The Chico area lies in the northwestern part of Butte County and ex- tends from the Sacramento River eastward into the foothills. Elevations in the area range from about 100 feet to 2,500 feet. The climate is char- acteristic of the Sacramento Valley : winters are cool and moist, with some snow in the higher areas, and summers are long, hot, and dry. The soils of the area range from recent secondary deposits (group I) such as those of the Farwell, Vina, Conejo, Honcut, Columbia, and Ramada series, through those having more and more fully developed profiles, to the hardpan soils. The intermediate soils are included in the Anita, Nord, and Sacramento series (group II), Corning and Keefers series (group III) , and the hardpan soils (group IV) of the San Joaquin and Redding series. The soils having consolidated substratum (group V) are included in the Tuscan, Landlow, and Stockton series. The Aiken, Sites, Mariposa, and Pentz series represent soils derived from the weath- ering of the underlying bedrock, group VI. The Columbia, Honcut, and Vina soils are used extensively for de- ciduous fruits, alfalfa, and grain. Almonds do well on the Vina soils. The Stockton and Sacramento soils are used for rice, a crop which does well on these soils in this area. Most of the Aiken soils under cultivation in this area are in fruit. The poorer soils of the area are devoted almost exclusively to pasture. Table 14 gives the soil group, index rating, and grade of each soil type found in the Soil Survey of the Chico Area. 15 There are 307,200 acres included in this survey, of which 76,736 acres are in grade 1 ; 20,928 acres in grade 2 ; and 33,472 acres in grade 3. The location of the different grades of soil for the Chico area may be found in area 9 on map 1. 15 Watson, E. B., et al. Soil survey of the Chico area, California. U. S. Dept. Agr. Bur. Chem. and Soils, Ser. 1925, Rept. 4:1-48. 1929. Bul, 599] A Rating of California Soils 35 TABLE 15 Clear Lake Area: Eating of Soils in Accordance with the Storie Index Soil type Soil group Factors, pei cent Index per cent Grade Remarks A B C Yolo finesandy loam I I I I I II II II II II II II II II I I I III III III III III VI VI VI VI VI VI VI I II VI III III 100 100 100 100 100 90 90 90 90 90 95 95 90 90 95 95 95 80 80 80 80 80 70 50 60 40 70 70 50 95 95 40 70 70 100 100 70 100 85 100 70 100 100 85 100 65 65 100 60 60 60 85 70 100 100 70 55 55 85 85 85 55 55 90 90 30 90 70 100 90 100 75 80 80 80 80 80 80 100 100 100 100 90 90 90 100 100 80 60 100 100 100 100 80 100 100 80 70 60 100 70 70 100 90 70 75 68 72 50 72 72 61 95 62 59 90 51 51 51 68 56 64 48 56 39 28 51 27 60 39 22 • 60 51 12 44 34 1 2 2 2 2 3 2 2 2 1 2 3 1 3 3 3 2 3 2 3 3 4 4 3 4 2 4 4 2 3 5 3 4 Yolo finesandy loam, poorly Yolo loam, poorly drained phase Drainage fair Yolo clay loam, poorly drained phase Drainage fair Cole finesandy loam, gravelly phase variable Drainage restricted Cole fine sandy loam, heavy- textured phase Subsoil heavy; drainage re- Cole fine sandy loam, cal- careous-subsoil phase stricted Subsoil compact; drainage re- Cole clay loam stricted Drainage restricted Rincon gravelly sandy loam, Subsoil stratified Rincon very fine sandy loam... Deep; friable Drainage fair Clear Lake clay adobe, upland Subdrainage fair Drainage restricted Manzanita gravelly fine sandy Moderately fertile Moderately fertile; drainage re- Pinole gravelly finesandy loam Konokti gravelly clay loam Konokti gravelly clay loam, stricted 40 to 50 in. deep Av. depth 2H ft. ; stony Av. depth 3 ft. Hugo clay loam, shallow phase Av. depth 2 ft.; hilly 3 to 4 ft. deep Aiken gravelly clay loam Aiken gravelly clay loam, 3 to 4 ft. deep Shallow; stony Drainage restricted Bayside silty clay loam, cal- Not typical of series; drainage restricted 20 to 30 in. deep Poorly drained Klamath silty clay loam, grav- Poorly drained; includes poorer areas 36 University of California — Experiment Station TABLE 15 — Clear Lake Area — (Concluded) Soil type Soil group Factors, per cent Index per cent Grade Remarks A B C III VII VII VII 60 85 60 31 8 3 1 4 6 6 6 Deep; drainage poor Rough mountainous land Nonarable Nonarable Nonagricultural 10. CLEAR LAKE AREA The Clear Lake area is located in the central portion of Lake Comity, which lies in the Coast Range about 70 miles north of San Francisco Bay and midway between the ocean and the Sacramento Valley. The eleva- tion of Clear Lake is about 1,300 feet, and the valley lands surrounding the lake rise to an additional 200 feet in elevation. Mt. Konokti is the highest point in the area and has an elevation of over 4,000 feet. Rainfall averaging about 28 inches a year occurs largely in the winter months, the summers being warm and dry. Extremes in temperature are rare and of short duration. Clear Lake occupies a central position in the area included in this sur- vey. Surrounding the lake, particularly in the northAvest and southwest, are flat valley lands made up of recent alluvial soils of the Clear Lake, Dublin, Yolo, and Bayside series (group I). Intermingled with those of group I are the slightly older soils of the Cole and Rincon series (group II). More completely weathered are the soils of the Manzanita, Pinole, Klamath, and Holcomb series (group III). Drainage is an important factor in the soils adjacent to the lake. At higher elevations and occupying rolling to hilly topography are the residual soils of the Konokti, Hugo, Aiken, and Butte series (group VI). The rougher, steeper, and more stony areas are included in group VII under the designations "rough mountainous land" and "rough stony land." The Clear Lake area is noted for its pears. This crop is grown largely on the recent to slightly weathered alluvial soils. Alfalfa, hops, walnuts, and prunes, as well as other crops, are extensively grown on these soils. Grapes, walnuts, and grain are grown on the Aiken and Konokti soils. Table 15 gives the soil group, index rating, and grade of each soil type found in the Soil Survey of the Clear Lake Area. 16 There are 247,040 acres included in this survey, about half of which is too rough and stony 16 Carpenter, E. J., E. Earl Storie, and Stanley W. Cosby. Soil survey of the Clear Lake area, California. U. S. Dept. Agr. Bur. Chem. and Soils, Ser. 1927, Eept. 13:1-45. * * Bul. 599] a Rating of California Soils 37 for agricultural purposes. About 10,624 acres are rated as grade 1 ; 36,160 acres as grade 2 ; and 41,208 acres as grade 3. The location of the various grades of soil in the Clear Lake area may be found in area 10 on map 3. 38 University of California — Experiment Station 11. COACHELLA VALLEY AREA The Coachella Valley area covers the major portion of the Coachella Valley in central Kiverside County. This area lies on the eastern or desert side of the mountains, from Salton Sea northwestward to Point Happy. The major portion of the area is below sea level. This is a region of very low rainfall. The winters are mild and the summers long, dry, and hot. No crops of any kind are possible without irrigation. TABLE 16 Coachella Valley Area : Eating of Soils in Accordance with the Storie Index Soil type Soil group Factors, per cent Index per cent Grade Remarks Coachella fine sand Coachella fine sand, smooth phase Coachella very fine sand Coachella very fine sand, smooth phase Indio very finesand Indio very fine sandy loam Indio loam Indio clay loam Indio clay loam, silty phase Indio clay Superstition very stony sand.. Superstition stony sand Superstition gravelly coarse sand Superstition gravelly sand Superstition sand Woodrow fine sandy loam (S).. Woodrow loam (S) Woodrow clay (S) Dunesand Rough broken and stony land 100 100 100 100 100 100 100 100 100 100 95 95 95 95 95 95 95 95 65 66 80 100 100 85 90 50 5 10 10 30 60 100 100 50 100 100 100 100 100 100 100 100 100 100 100 100 100 5 52 100 100 85 90 50 5 10 10 29 57 5 5 2 5 1 Deep ; leachy ; sand-dune surface Deep Sand-dune surface; deep Silty clay loam Very stony ; nonarable Very stony Coarse; leachy Coarse ; leachy Leachy No areas without alkali ; drain- age poor No areas without alkali; drain- age poor No areas without alkali; drain- age poor Rough ; nonagricultural Nonarable The area surveyed is a narrow gently sloping valley made up entirely of soils of the Indio, Coachella, Woodrow, and Superstition series. The Coachella series has been modified considerably by wind action, certain types having a rough sand-dune topography. The "Woodrow series is highly alkaline, being a lacustrine deposit situated just above the level of the Salton Sea. The area is bordered on two sides by steep mountains with outwashes of recent to slightly aged soils of the Superstition series. All of the soils are included in group I, although the Superstition series Bul. 599] A Rating of California Soils 39 includes areas having compact subsoil which should be in group II. Alkali is an important factor in all of the soils of the valley. The Coachella Valley is an area of specialized crops in which climate has been a greater influence than soils. Dates are an important crop in this region. Grapefruit, grapes, onions, and a few other truck crops are important because of their earliness. The smooth phases of the Coachella TABLE 17 Effect of Varying Degrees of Alkali on the Index Value of Soils in the Coachella Valley Area Soil type F, alkali- free, per cent M, slightly affected, per cent A, moderately affected, per cent S, strongly affected, per cent Coachella fine sand Coachella fine sand, smooth phase Coachella very fine sand Coachella very fine sand, smooth ph Indio very fine sand Indio very fine sandy loam Indio loam Indio clay loam Indio clay loam, silty phase Indio clay Superstition very stony sand Superstition stony sand Superstition gravelly coarse sand Superstition gravelly sand Superstition sand Woodrow fine sandy loam Woodrow loam Woodrow clay Dunesand Rough broken and stony land 100 100 85 90 50 5 10 10 29 57 and Indio series, when free from alkali, are well adapted to the crops grown, but the cultivated area is limited by the availability of water for irrigation. Some of the more alkaline areas, when irrigated, are used for miscellaneous field crops and pasture. Table 16 gives the soil group, index rating, and grade of each soil type found in the Soil Survey of the Coachella Valley Area. 17 This table has been prepared for alkali-free conditions only. Table 17 gives the values for each type when slightly affected (M), moderately affected (A), and strongly affected (S) with alkali. The Coachella Valley survey covers 220,160 acres, a large part of which is nonagricultural on account of topography or alkali. Grade 1 includes 26,582 acres; grade 2, 18,087 acres ; and grade 3, 50,224 acres. For the soil grades in the Coachella Valley area see area 11, map 4. 17 Kocher, A. E., and W. G. Harper. Soil survey of the Coachella Valley area, Cali- fornia. U. S. Dept. Agr. Bur. Soils, Field Oper. 1923:485-535. 1928. 40 University of California — Experiment Station TABLE 18 Colusa Area : Eating of Soils in Accordance with the Storie Index Soil type* Soil group Factors, per cent Index per cent Grade Remarks San Joaquin gravelly loam... San Joaquin fine sandy loam San Joaquin loam Sacramento gravelly sandy loam Sacramento loam Sacramento fine sandy loam Sacramento silt loam Sacramento silty clay loam ... Sacramento silty clay Willows loam Willows silty clay loam Willows clay loam Willows clay adobe Willows clay Norman clay adobe Orland fine sand Orland fine sandy loam Sites sandy loam Sites loam Sites clay loam adobe Rough stony land Riverwash II III I II VI VI VI VII VII 100 100 100 100 100 100 100 95 95 100 80 40 50 50 70 100 100 65 100 100 100 90 65 100 90 85 60 50 60 65 100 100 85 70 100 100 90 100 100 100 100 80 100 100 100 70 60 80 80 100 80 100 100 39 100 100 100 90 52 100 Av. depth to hardpan 3 ft. Av. depth to hardpan 2 ft. Av. depth to hardpan about 5 ft. ; often gravelly Leachy ; subject to overflow; should be Columbia Texture and subsoil variable; should be Columbia Texture variable; somewhat leachy ; should be Columbia May be dissected by sloughs ; should be Columbia Small areas underlain with heavy material at 5 or 6 ft. ; should be Columbia Drainage usually poor; alkali; should be Columbia Subsoil somewhat variable; should be Marsh Creek Subsoil usually compact; may contain alkali ; should be Marsh Creek Subsoil usually compact; may contain alkali; should be Marsh Creek Compact; poor drainage and alkali Compact; poor drainage; alkali Compact ; poor drainage ; al kali Texture and subsoil vary greatly Av. about 2 ft. to bedrock; often steep and rocky About 3 ft. deep; clay loam tex- ture About 3 ft. deep; variable Nonarable Nonagricultural * The names given some of the soil series in the older surveys (Colusa area, 1909) may not conform to later correlations; the values should not be confused with those for soils having similar names in other 12. COLUSA AREA The Colusa area is centrally located on the west side of the Sacramento Valley in Glenn, Colusa, and a small part of Tehama counties. It includes all of the land in this section lying between the Coast Range foothills occupied by the residual soils of the Sites series (group VI) and the Sacramento River. On this broad plain are the recent alluvial soils, group I, of the Sacramento series (similar soils are mapped in more recent Bul, 599] a Rating of California Soils 41 surveys as Columbia) located nearest the river, and the Willows (groups I and II), Norman (group III), and Orland series (group I). The Nor- man series and the heavier members of the Willows series occupy a de- pression known as the Colusa Basin. The basin soils are subject to poor drainage and often high accumulations of alkali. The lighter-textured Willows and the Orland soils occupy the higher, gently sloping fans between the base of the mountains and the Colusa Basin. In the northern part of the survey is a slightly elevated terrace area of old alluvial soils in which a hardpan has developed. These have been mapped as the San Joaquin series (group IV) . The residual soils of the Sites series are mostly nonirrigated and are used largely for pasture and grain. The irrigated areas are satisfactory for fruits. The better-drained and light-textured members of the Willows series are devoted to dry-farmed barley and wheat, or irrigated alfalfa and general farm crops. The poorly drained soils are used either for pasture or for rice. The Sacramento series of soils is devoted to general farming and fruit, and the San Joaquin series is used for grain and pasture. Table 18 gives the soil group, index rating, and grade for each soil type as described in the Soil Survey of the Colusa Area, 18 with brief remarks on variations and modifying factors. This survey covers an area of 484,032 acres, of which 162,176 acres are in grade 1 ; 7,158 acres in grade 2; and 104,448 acres in grade 3. Heavy texture and alkali are largely responsible for the lower rating given the remainder of the area. The location of the several grades of soil in the Colusa area may be found in area 12 on map 1. is Lapham, Macy H., et al. Soil survey of the Colusa area, California. U. S. Dept. Agr. Bur. Soils, Field Oper. 1907:927-72. 1909. (Out of print.) 42 University of California — Experiment Station TABLE 19 Concord Area : Rating of Soils in Accordance with the Storie Index Soil type* Soil group Factors, per cent Index per cent Grade Remarks Los Osos loam Los Osos loam, shallow phase.. Los Osos clay adobe Los Osos clay adobe, steep phase Cayucosloam Cayucos clay adobe Hugo loam Hugo clay loam Hugo clay loam, steep phase.... Contra Costa loamy sand Contra Costa loamy sand, heavy-textured phase Contra Costa clay loam Contra Costa clay loam, steep phase Arnold sandy loam Olympic stony clay loam Norris clay adobe Norris clay adobe, steep phase Diablo clay adobe Altamont clay loam Altamont clay loam, steep phase Altamont clay adobe Linne clay adobe Nacimiento clay loam Montezuma clay adobe Montezuma clay adobe, brown phase Ambrose clay loam Ambrose clay loam, gray phase Ambrose clay adobe Antiochloam Rincon clay loam Rincon silty clay Rincon silty clay, heavy- textured phase Marsh Creek clay loam Marsh Creek clay loam, light- textured phase Marsh Creek clay loam, gray phase Marsh Creek silty clay Marsh Creek silty clay, gray phase Salinas clay loam Manzanita gravelly clay loam.. VI VI VI VI VI VI VI VI VI VI VI VI VI VI VI VI VI VI VI VI VI VI VI III III III III III III II II II I I I I II III 65 80 100 100 100 100 100 95 50 100 85 70 70 100 70 100 85 85 85 70 60 70 85 85 70 70 85 70 70 85 85 70 100 85 70 85 100 85 100 100 100 50 100 100 90 80 60 100 60 70 60 100 100 60 100 100 100 100 100 100 90 100 100 100 100 100 100 100 100 100 100 51 51 42 54 77 63 54 85 100 85 65 65 81 28 Av. depth %y 2 ft. Av. depth 15 in.; clay loam to clay texture Av. depth Zy 2 ft. ; includes lighter-textured areas Av. depth 2 ft. ; steep Av. depth 2 ft. ; texture variable Av. depth 3 ft. ; texture variable Av. depth 2 ft. ; low yields Av. depth 3 ft. ; erosive Av. depth 18 in. ; eroded; steep Av. depth 2 ft. ; low in humus Av. depth 2 ft. ; sandy loam Av. depth 3 ft. Av. depth 2 ft. ; steep; eroded Av. depth 2Y 2 ft.; infertile Av. depth 3 ft. ; stony ; steep Av. depth 3H ft. ; slightly erosive Av. depth 2]/ 2 ft.; steep; erosive Av. depth 3H ft. Av. depth %y 2 ft. Av. depth 2 f t. ; steep ; erosive Av. depth Sy 2 ft. Av. depth Z x / 2 ft. ; contains rock fragments Av. depth V>/ 2 ft. ; erosive Heavy texture; drainage good Similar to Denverton in other Dense subsoil Friable Clay Loam * In this area the field names have been used because at this time (February, 1935) neither the pre- liminary nor final correlation has been made. Bul. 599] A Rating op California Soils TABLE 19 — Concord Area — (Concluded) 43 Soil type* dark- Corning gravelly loam- Corning gravelly loam colored phase Tierraloam Olcottloam Herdlyn fine sandy loam Zamoraloam Zamoraloam, heavy-textured- subsoil phase Zamora clay loam Zamora silty clay loam Zamora silty clay loam, poorly drained phase Clayton silty clay loam Clayton silty clay loam, cal- careous-subsoil phase San Ramon loam San Ramon clay loam Danville clay loam Sorrento loam Sorrento silty clay loam Yolo loam Yolo clay loam Oakley sand Columbia loam Dublin clay adobe Dublin clay adobe, light- textured phase Dublin clay adobe, overwash phase Clear Lake clay adobe Clear Lake clay adobe, light- textured phase Solano loam Bixler finesandy loam Bixlerclay Osage clay loam Osage clay loam, heavy- textured phase Sacramento loamy sand Sacramento clay adobe Ryde clay loam Egbert clay loam Peat Alvisoclay Sacramento loamy sand, Eg- bert clay loam, and peat, un- differentiated Peat, muck, and Alviso clay, undifferentiated Made land Rough broken land Rough stony land Soil group III III V III III I III I I I II II I I I I I I I I I I I I I III I I III III II II I I I VII VII VII Factors, per cent 50 50 60 50 100 70 100 100 100 80 100 100 100 100 100 100 100 100 100 100 100 100 95 95 40 100 100 50 50 80 90 100 100 100 100 100 100 70 70 100 100 100 100 100 85 90 100 85 85 100 90 100 85 60 100 70 85 85 70 85 100 100 60 85 70 100 100 100 60 60 100 100 75 90 100 100 100 100 100 60 100 100 100 100 100 100 100 100 100 90 100 90 100 90 100 50 40 40 50 50 20 Index per cent 35 35 38 54 50 100 70 85 54 72 72 100 85 85 100 90 100 85 54 100 63 85 77 53 81 20 40 24 21 15 13 50 80 80 48 Grade Remarks High gravel content Texture variable Texture variable; erosive Erosive Friable Resembles Pinole series Contains some gravelly Friable Drainage poor Includes some gravelly Includes gravelly areas Includes gravelly areas Friable Friable Somewhat hummocky Friable Difficult to work Clay loam texture Surface texture clay loam Drainage restricted Clay loam texture Drainage poor ; some alkali Drainage poor ; alkali Drainage poor; alkali Deflocculated; erosive Clay; erosive Alkali ; not typical of series High water table High in humus; high water table High in humus; drainage poor; high water table Organic ; high water table Drainage very poor Variable; drainage poor Drainage very poor; alkali Sand and clay ; dredger deposits Nonarable Nonarable * In this area the field names have been used because at this time (February, 1935) neither the prelimi- nary nor final correlation has been made. 44 University of California — Experiment Station 13. CONCORD AREA The Concord area includes all of Contra Costa County except the City of Richmond. The topographic and physiographic features of the area are varied, as it extends from the crest of the Berkeley Hills eastward to include Walnut Creek and San Ramon valleys, the Mt. Diablo range with its alluvial outwash, a portion of the delta of the San Joaquin River, and also portions of the coastal plains along the San Francisco Bay shore. Elevations in the area vary from slightly below sea level to the summit of Mt. Diablo, which has an elevation of 3,849 feet. This is a region of moderate rainfall and moderate temperatures. The physical, climatic, and geological conditions have been such as to give rise to a wide variety of soils. In group VI, the residual soils are to be found in the Los Osos, Cayucos, Hugo, Contra Costa, Arnold, Olympic, Norris, Diablo, Altamont, Linne, and Nacimiento series. In group I, the unweathered alluvial soils are members of the Marsh Creek, Zamora, San Ramon, Danville, Sorrento, Yolo, Oakley, Columbia, Dub- lin, Clear Lake, Bixler, Ryde, Egbert, and Alviso series. In group II, the slightly weathered alluvial soils, are the Rincon, Salinas, Clayton, and Sacramento series ; and in group III are found members of the Monte- zuma, Ambrose, Antioch, Manzanita, Corning, Olcott, Herdlyn, Solano, and Osage series. The Tierra series is the only representative of group V developed on consolidated substratum. An important member of group I in this area is the peat land of the delta region. A rather wide use is made of the land in this area, deciduous fruits, grapes, walnuts, and field and truck crops being grown on the alluvial soils, with fruits, grain, grain hay, and pasture being grown on the soils of the residual group. The peat lands are devoted to truck crops. Table 19 gives the soil group, index rating, and grade for each soil type as provisionally shown in the Soil Survey of the Concord Area. 19 The survey of this area, which will cover 461,440 acres, is not yet pub- lished, and the soil-series names given here are provisional and subject to final correlation. The acreages of the several soil types have not yet been computed. The location of each grade of soil in the Concord area may be found in area 13 on map 3. !9 Carpenter, E. J., and Stanley W. Cosby. Soil survey of the Concord area, California. (In press.) Bul, 599] A Rating of California Soils 45 TABLE 20 Dixon Area: Eating of Soils in Accordance with the Storie Index Soil type Hugo fine sandy loam Hugo clay loam Hugo clay loam, steep phase... Los Osos clay loam Los Osos clay loam, steep phase Denverton clay adobe Hartley fine sandy loam Hartley fine sandy loam, brown phase Olcott fine sandy loam Olcott fine sandy loam, red phase Solano fine sandy loam Solano fine sandy loam, brown phase Columbia silty clay loam Yolo finesandy loam Yolo finesandy loam, shallow phase Yolo silty loam Yolo silty clay loam Yolo silty clay loam, cal- careous-subsoil phase Zamora silty clay loam Zamora clay loam Zamora clay loam, heavy- textured phase Esparto silty clay loam Esparto silty clay loam, light- textured phase Capay loam Capay clay loam Capay silty clay loam Capay clay Capay clay, red phase Clear Lake clay adobe Sacramento clay loam Sacramento clay loam, friable- subsoil phase Sacramento clay Denverton and Hartley soils, undifferentiated Los Osos and Hugo soils undif- ferentiated, steep phase.... Riverwash Soil group VI VI VI VI VI III III III III III III III II II II II II III III III III III I II III VI VII Factors, per cent 35 100 100 100 100 100 95 95 95 95 95 95 70 70 70 70 70 95 95 100 95 100 85 85 85 85 70 100 100 100 100 100 100 90 100 100 100 95 90 100 100 100 85 90 50 50 60 85 100 70 90 100 50 100 50 100 90 90 90 90 50 GO 100 100 GO 100 100 100 100 100 100 90 90 90 Index per cent 100 100 95 68 50 Grade Remarks Av. depth 24 in. ; erosive Av. depth 24 in. Essentially nonarable Av. depth 24 in. Essentially nonarable Drainage poor; alkali; puddles badly Drainage poor ; alkali ; puddles badly Friable Friable About 3 ft. of Yolo over Capay or Olcott Friable; fertile Includes silt loam Drainage restricted; not typical of series Clay adobe texture Silty loam Low in humus ; slightly acid Drainage somewhat restricted Drainage somewhat restricted Drainage restricted Drainage restricted Subject to overflow Areas in By- pass subject to over- flow Not typical of series High in humus Index rating only approximate Nonarable Nonagricultural 46 University of California — Experiment Station 14. DIXON AREA The Dixon area covers the northern half of Solano County and that portion of Yolo County lying south of Putah Creek. The area extends from the crest of the Vaca Mountains on the west to the Sacramento River on the east, and the topography ranges from the steep mountains surrounding Vaca Valley through the foothills and gently sloping plains to the flat depression of Yolo Basin. The soils also have a wide range of characteristics. The Hugo and Los Osos soils are derived from the weathering of the underlying bedrock (group VI) and occupy the hilly to mountainous area. In group III are soils representing strongly weathered alluvial material having heavy clay subsoils of underlying substratum. Of these, the Denverton and Hartley soils occupy slightly elevated and eroded terraces, while the Olcott, Solano, and Capay series occupy natter, more poorly drained areas. In group II, the slightly weathered somewhat compacted soils, the Zamora, Esparto, and Sacramento series are found occupying flat to only slightly elevated positions having somewhat restricted drainage. The Columbia, Yolo, and Clear Lake series compose the soils of group I and represent recent alluvial deposits. Deciduous fruit is extensively grown without irrigation in the foot- hills and in Vaca and Pleasant valleys. Alfalfa and truck crops occupy the better-drained irrigated lands of the main valley, while grain and pasture are produced on the less-well-drained areas and on many of the better, nonirrigated soils. The area enjoys a moderate rainfall which occurs mostly during the winter months. The summers are dry and warm. Irrigation water is scarce, the only source being from wells, and most of the area is dry- farmed. Table 20 shows the soil group, index rating, and grade of the various soil types found in the Soil Survey of the Dixon Area. 20 This survey covers an area of 278,400 acres, of which 70,144 acres are in grade 1 ; 38,592 acres in grade 2 ; and 84,480 acres in grade 3. The location of the different grades of soils in the Dixon area may be found in area 14 on map 1. 2 o Cosby, S. W., and E. J. Carpenter. Soil survey of Dixon area, California. IT. S. Dept. Agr. Bur. Chein. and Soils, Series 1931, Eept. 7:1-47. Bul. 599] A Rating of California Soils 47 TABLE 21 El Ca jon Area : Eating of Soils in Accordance with the Storie Index Soil type Soil group Fallbrook sandy loam. Fallbrook sandy loam, stony phase Vista sandy loam Vista sandy loam, stony phase Escondido very fine sandy loam Escondido very fine sandy loam, stony phase Konokti stony loam Carlsbad loamy fine sand... Altamont clay loam Diablo clay adobe Diablo clay adobe, brown phase Ayarclay Linne sandy clay loam Hanford sandy loam Hanford sandy loam, gravelly phase Hanford sandy loam, dark- colored phase Foster very fine sandy loam.. Foster very fine sandy loam, gray phase Cajon fine sand.. Agueda clay loam Alviso very fine sandy loam. Marina loamy fine sand Greenfield sandy loam Ramona sandy loam Hames sandy loam Hames sandy loam, friable- subsoil phase Botella fine sandy loam San Marcos fine sandy loam Salinas sandy clay loam Sorrento clay loam Redding gravelly sandy loam Redding sandy loam Oli venhain gravelly sandy loam Olivenhain fine sandy loam VI VI VI VI VI VI VI VI VI VI I I I I I II III Factors, per cent 60 60 50 50 40 30 40 40 50 50 40 40 100 100 100 100 100 100 100 100 90 100 90 100 95 95 95 100 20 95 100 70 60 85 85 50 65 95 100 100 65 85 100 95 100 100 85 85 65 100 100 100 100 100 100 100 100 100 80 80 100 100 100 100 100 100 90 80 95 5 75 100 100 100 100 100 40 100 100 90 100 100 100 Index per cent 57 52 Grade Remarks 30 to 50 in. deep; some stony Depth varies ; often very stony 30 to 60 in. deep; erosive Depth varies; stones limit its value 20 to 44 in. deep About 2 ft. deep Shallow; high stone content 20 to 40 in. deep. ; eroded Erosion active Av. depth 2Yi ft. ; high in humus Differs from typical soil mainly in color 18 to 40 in. deep 18 to 36 in. deep Texture somewhat variable; may contain alkali Gravelly subsoil ; cobbly in places May contain alkali; texture somewhat variable May contain alkali; texture somewhat variable Texture varies; subject to wash and overflow Texture somewhat variable High in salts ; tidal land Acid soils ; rolling surface Variable gravel content ; may be eroded Younger soil than typical Hames Some alkali ; fair to poor drainage Shallow; very acid soils Shallow Shallow; heavy clay subsoil Shallow; heavy clay subsoil 48 University of California — Experiment Station TABLE 21 — El Cajon Area — (Concluded) Soil type Soil group Factors, per cent Index per cent Grade Remarks A B C Las Flores loamy fine sand V III III III III V VII VII VII VII VII 20 35 40 40 50 40 90 100 85 100 95 95 90 100 95 100 100 100 16 35 32 40 48 38 5 2 2 1 3 5 4 4 3 3 4 6 6 6 6 6 Shallow soil; heavy clay subsoil; infertile Compact heavy clay subsoil Aliso fine sandy loam, heavy Clay loam to clay; compact Huerhuero fine sandy loam heavy clay subsoil Compact heavy clay subsoil Compact heavy clay subsoil Compact heavy subsoils Steep; stony ; no narable Nonarable Nonagricultural Coastal beach, dunesand. Nonagricultural Tidal marshes that have been filled in 15. EL CAJON AREA The El Cajon area is located in the southwest corner of the state and in- cludes the coast and foothill region in the vicinity of San Diego. This is a region of equable climate, with dry summers and mild winters. The area covers the mountainous region in the eastern half, a coastal plain area of flat-topped sea terraces on the west, with lower marine terraces around San Diego Bay. Deep narrow valleys made up of alluvial soils extend eastward from the coast. The residual soils (group VI) of the mountainous and hilly areas are included in the Fallbrook, Vista, Escondido, and Konokti series, and those of the lower areas in the Carlsbad, Altamont, Diablo, Ayar, and Linne series. The hardpan soils of the Redding series (group IV) and the Oliven- hain, Las Flores, and Monserate series (group V), which have very heavy clay subsoils resting on a marine substratum, represent the old maturely weathered soils. The Hames, Aliso, Huerhuero, and Merriam series are included in group III. The slightly weathered soils (group II) include the Ramona, San Marcos, and Salinas series; and the recent alluvial soils (group I) are included in the Hanford, Foster, Cajon, Agueda, Alviso, Marina, Greenfield, and Sorrento series. Nearly one-third of the area is mapped as group VII — nonagricultural types. Climate and the availability of irrigation water have been determining factors in the use of the soils of this area. Citrus fruits, avocados, berries, grapes, truck crops, flowers, Bul, 599] a Rating of California Soils 49 bulbs, and ornamental plants are more or less specialized products of the region. Water for irrigation is limited, and practically no crops except grain and hay are grown without irrigation. Table 21 shows the soil group, the index rating, and the grade of the soil types found in the Soil Survey of the El Cajon Area. 21 There are 387,200 acres included in this survey, of which 19,904 acres are consid- ered as grade 1 ; 30,080 acres as grade 2 ; and 21,056 acres as grade 3. The location of the several grades of soils in the El Cajon area may be found in area 15 on map 4. 2i Storie, E. Earl, and E. J. Carpenter. Soil survey of the El Cajon area, Cali- fornia. U. S. Dept. Agr. Bur. Chem. and Soils, Ser. 1930, Eept. 15:1-42. 50 University of California — Experiment Station 16. EL CENTRO AREA The El Centro area covers the southern half of Imperial Valley, Im- perial County. This is the region of long, hot, dry summers, and mild, dry winters. Rainfall is negligible, and no crops are grown without irri- gation. The soils are largely recent alluvial or lacustrine, having been TABLE 22 El Centro Area : Eating of Soils in Accordance with the Storie Index Soil type Imperial silty clay loam Imperial silty clay Imperial clay Holtville very fine sandy loam Holtville silty clay loam Holtville silty clay Holtville clay Tijeras gravelly fine sandy loam Superstition gravelly coarse sand Superstition coarse sand Superstition gravelly sand Superstition fine sand Meloland gravelly sand Meloland fine sand Meloland finesandy loam Rositas gravelly fine sand Rositassand Rositas fine sand Rositas very finesand Rositas very fine sandy loam.... Carrizosand Riverwash Rough broken land Dunesand Soil group Factors, per cent * Index per cent * Grade A B C I 75t 90 100 68 2 I 75t 65 100 49 3 I rat 55 100 41 3 I 95 100 100 95 1 I 95 90 100 86 1 I 95 65 100 62 2 I 95 50 100 48 3 V 40 70 100 28 4 II 90 30 70 19 5 II 90 50 85 38 4 II 90 50 100 45 3 II 90 65 100 59 3 I 85f 30 100 26 4 I 85f 65 100 55 3 I 85t 100 100 85 1 I 100 50 80 40 3 I 100 60 85 51 3 I 100 65 85 55 3 I 100 80 85 68 2 I 100 100 95 95 1 I 100 60 45 27 4 VII 5 6 VII 3 6 VII 20 4 Remarks Heavy subsoil Heavy subsoil Very heavy subsoil May be stratified May be stratified Very coarse-textured and eroded Coarse-textured; may be eroded Very coarse-textured; heavy subsoil Heavy subsoil Heavy subsoil Wind-blown Wind-blown Wind-blown Wind-blown Light-textured surface Very coarse-textured ; eroded Subject to overflow Very rough Rough topography * Computed on alkali-free basis. t Factor A of Imperial and Meloland series reduced below normal for group I on account of very heavy subsoils. transported and deposited by the Colorado River. In some places wind has modified the sandy material. The Imperial, Holtville, Meloland, and Rositas series are included in group I. A rim of secondary soils derived from the surrounding hilly and mountainous areas border the Colorado River deposits. These soils include Carrizo series (group I), the Superstition series (group II), and the Tijeras series (group V) . Bul, 599] A Rating of California Soils 51 Alkali is an important factor in all of the soils of the region. A wide range of crops, including grapefruit, grapes, alfalfa, cantaloupes, let- tuce, grain, and corn, is grown where alkali is not a deterring factor. Table 22 gives the soil group, index rating, and grade of each soil type found in the Soil Survey of the El Centro Area, 22 for alkali-free condi- tions only. TABLE 23 Effect of Varying Degrees of Alkali on the Index Value of Soils in El Centro Area Soil type F, alkali- free, per cent M, slightly affected, per cent A, moderately affected, per cent 68 60 40 49 43 29 41 36 24 95 85 57 85 69 51 62 55 38 48 43 29 26 23 16 55 49 33 85 76 51 40 51 46 31 55 49 34 68 61 41 95 85 57 19 45 40 27 38 34 23 59 53 35 28 25 16 27 23 15 20 18 12 5 4 3 3 2 1 s, strongly affected, per cent Imperial silty clay loam Imperial silty clay Imperial clay Holtville very fine sandy loam Holtville silty clay loam Holtville silty clay Holtville clay Meloland gravelly sand Meloland fine sand Meloland fine sandy loam Rositas gravelly fine sand Rositas sand Rositas fine sand Rositas very fine sand Rositas very fine sandy loam Superstition gravelly coarse sand Superstition gravelly sand Superstition coarse sand Superstition fine sand Tijeras gravelly fine sandy loam.. Carrizo sand Dunesand Riverwash Rough broken land Table 23 gives the rating for different degrees of alkali. The values given are for slightly affected (M), moderately affected (A), and strongly affected (S) areas. This survey covers 322,560 acres, of which 32,444 are in grade 1 ; 68,076 in grade 2 ; and 108,729 in grade 3. The location of the grades of soil for the El Centro area may be found in area 16 on map 4. 22 Strahorn, A. T., et al. Soil survey of the El Centro area, California. U. S. Dept. Agr. Bur. Soils, Field Oper. 1918:1-59. 1922. 52 University of California — Experiment Station 17. EUREKA AREA The Eureka area is located along the coast in west-central Humboldt County. It covers most of the agricultural land in the county and in- cludes the alluvial and terrace lands of the lower parts of Mad and Eel river valleys, and around Humboldt Bay, together with marginal areas TABLE 24 Eureka Area: Eating of Soils in Accordance with the Storie Index Soil type Soil group Factors, per cent Index per cent Grade Remarks Kneeland clay loam Melbourne clay loam Empire fine sandy loam Empire fine sandy loam, light- textured phase Empire fine sandy loam , eroded phase Rhonerville fine sandy loam.... Rhonerville clay loam Rhonerville clay loam, poorly drained phase Willits clay loam Willits clay loam, eroded phase Willits clay loam, overwash phase Westportsand Coquille clay loam Ferndale fine sandy loam Ferndale fine sandy loam, gravelly phase Ferndale silt loam Bayside fine sand Baysideloam Coastal beach, dunesand, and riverwash Tidal marsh and swamp Rough mountainous land.... 35 70 70 70 70 90 90 90 80 80 90 95 95 100 100 100 100 100 85 85 100 100 100 100 85 85 85 85 100 60 85 100 70 100 80 100 80 VII VII VII 49 6 to 36 in. deep; erosion active Deep; acid; erosive Acid; erosive Acid Eroded and steep Leached; acid Leached; acid Drainage poor Leached soil Badly eroded and steep 1 ft. overwash of silt loams Subdrainage poor Value enhanced when drained Deep; friable; acid Subject to overflow; varying quantities of gravel Somewhat acid Subdrainage usually poor; tex- ture variable Profile variable; drainage de- ficient Nonagricultural Nonagricultural unless drained Nonarable of mountainous country. This area lies in a region of high rainfall, and moderate summer and winter temperatures. A considerable portion of the area at one time supported a heavy growth of redwoods. The residual soils (group VI) are limited to those of the Kneeland and Melbourne series. The Empire series represents old alluvial mate- rials which have weathered into soils having heavy-textured subsoils (group III). The slightly weathered soils (group II) include the Rhon- Bul. 599] A Rating of California Soils 53 erville, Willits, and Westport; and the more recent soils (group I) the Coquille, Ferndale, and Bayside series. The drainage is deficient in most of the soils of the region. All of the soils of this area have an acid reaction. Dairying is the principal agricultural pursuit of the area; conse- quently considerable land is devoted to root crops, hay grasses, clover, and such other forage crops as the dairies require. Berries, truck crops, and potatoes are grown in commercial quantities. Table 24 shows the soil group, index rating, and grade for each soil type in the Soil Survey of the Eureka Area. 23 This survey covers 254,800 acres, of which 30,720 acres are in grade 1 ; 25,088 acres in grade 2 ; and 44,544 acres in grade 3. Nearly half of the area is mountainous. The location of the different soil grades in the Eureka area may be found in area 17 on map 1. 23 Watson, E. B., Stanley W. Cosby, and Alfred Smith. Soil survey of the Eureka area, California. U. S. Dept. Agr. Bur. Soils, Field Oper. 1921:851-81. 1925. 54 University of California — Experiment Station TABLE 25 Fresno Area: Rating of Soils in Accordance with the Storie Index Soil type Soil group Factors, per cent Index per cent Grade Remarks A B C Holland coarse sandy loam VI VI VI VI VII II IV IV IV I IV IV IV I I I I IV IV IV IV IV IV IV IV IV IV I III 50 50 50 50 85 25 25 25 100 70 70 40 100 100 100 100 100 60 60 60 60 60 20 20 20 20 20 100 100 100 100 100 100 100 100 100 100 100 60 90 100 60 95 60 95 85 60 60 95 100 100 60 60 60 60 60 95 95 95 95 95 100 100 100 100 100 40 60 65 95 95 95 95 100 100 100 100 100 100 100 100 100 100 100 100 80 70 100 100 100 100 80 60 40 10 100 80 60 40 10 100 80 60 40 10 100 90 90 100 80 60 40 100 75 55 35 80 45 50 30 48 5 51 24 21 12 42 67 70 40 60 48 36 24 6 57 46 34 23 6 20 16 12 8 2 40 54 59 95 76 57 38 100 75 55 35 48 3 3 4 3 6 3 4 4 5 3 2 2 3 2 3 4 4 6 3 3 4 4 6 4 5 5 6 6 3 3 3 2 3 4 1 2 3 4 3 Depth, stone content, and topography variable raphy variable Depth, stone content, and topography variable topography variable Includes nontypical material Av. depth to hardpan 2J^ ft. Av. depth to hardpan V/i ft.; drainage poor Madera; hardpan at 6 ft. or more; not typical of series Av. depth to hardpan 4 to 6 ft. ; includes overwash of Hanford Av. depth to hardpan 4 to 6 ft. ; includes overwash of Hanford Av. depth 3 ft. Fresno sand (B) on Fresno hardpan; over 6 ft. deep Strong alkali Fresno sand (E) Av. depth to hardpan 5 to 6 ft. Slight alkali Fresno sandy loam (C) Fresno fine sandy loam Fresno fine sandy loam (B) Fresno fine sandy loam (C) Fresno fine sandy loam (D) Fresno fine sandy loam (E) Hanford gravelly sand Slight alkali Moderate alkali Strong alkali Very strong alkali Hanford sand Hanford fine sand casional overflow Slight alkali Hanford sandy loam (D) Hanford fine sandy loam Hanford fine sandy loam (B).... Hanford fine sandy loam (C).... Hanford fine sandy loam (D) .. Deep and friable Slight alkali Moderate alkali Strong alkali Slight alkali Bul. 599] A Rating of California Soils TABLE 25 — Fresno Area — (Concluded) 55 Soil type Soil group Factors, per cent Index per cent Grade Remarks A B C Merced silt loam (C) III III III III III III III III III VII 60 60 60 80 80 60 60 60 80 100 100 90 90 90 60 60 60 60 60 10 60 40 10 60 40 10 100 36 6 32 29 7 22 14 4 48 1 4 6 4 4 6 4 5 6 3 6 Moderate alkali Merced silt loam (D) alkali Merced silty clay loam (C) Merced silty clay loam ( D) Moderate alkali Hardpan; drainage poor; over- flow; strong alkali alkali Nonagricultural 18. FRESNO AREA The Fresno area is located in Fresno County near the center of the San Joaquin Valley and includes practically all of the agricultural lands of the county. With the exception of a narrow rim of foothills on the eastern part, the area is flat to gently sloping valley land. The climate is arid, about 9 inches of rain falling in the winter months ; the summers are long, hot, and dry. Practically no crops are grown without irrigation, but irrigation water is available either by pumping or by gravity for most of the area suited to crops. The Holland, Sierra, Aiken, and Sheridan series constitute the resi- dual soils, group VI, of the area. The San Joaquin, Alamo, Madera, and Fresno series of soils are in group IV. These soils occupy positions inter- mediate between the residual soils of group VI and the recent alluvial soils of groups I and II. The Fresno series is characteristically poorly drained and alkaline, although the lighter-textured members may be relatively free from alkali. The Merced and Centerville series are in- cluded in group III. The Porterville series is in group II. The Hanford series and the sand type of the Madera and Fresno series as mapped in the survey are in group I. The heavier types of Hanford may contain alkali. The area produces a wide range of crops, including most of the de- ciduous fruits, grapes, alfalfa, grain, hay, and cotton. Table 25 shows the soil group, index rating, and grade of each type shown in the Soil Survey of the Fresno Area, 2 * together with brief re- 24 Strahorn, A. T., et al. Soil survey of the Fresno area, California. U. S. Dept. Agr. Bur. Soils, Field Oper. 1912:2089-166. 1914. (Out of print.) 56 University of California — Experiment Station marks concerning alkali and depth. In this table the same designations for degrees of alkali are used as were used in the soil-survey report : B designates a concentration of 200 to 400 parts per million ; C, 400 to 600 ; D, 600 to 1,000 ; and E, over 1,000 parts per million. This survey covers 867,840 acres, but available data do not show the acreage of each soil type affected with alkali, and since the rating de- pends in part upon alkali conditions, the acreage falling in each grade is not determined. The location of the various grades of soil in the Fresno area may be found in area 18 on map 2. Bul, 599] A Rating of California Soils 57 TABLE 26 Gilroy Area : Eating of Soils in Accordance with the Storie Index Soil type Soil group Yolo fine sandy loam Yolo gravelly loam Yolo silty loam Yolo silt loam, compact- subsoil phase Yolo clay loam Yolo clay adobe Pleasanton gravelly sandy loam.... Pinole fine sandy loam Pinole loam Pinole loam, rolling phase Vina gravelly loam Vina gravelly loam, heavy phase Aiken gravelly clay loam Antioch clay loam Conejo clay loam Conejo clay adobe Honcut clay loam Honcut clay loam, gravelly phase Corning clay loam Rincon clay loam Rincon clay loam, rolling phase Olympic gravelly clay loam. Olympic clay adobe Dublin clay loam Dublin clay loam, gravelly phase Dublin clay adobe Altamont loam Arnold clay loam. San Ysidro loam... Climax clay adobe Lagunaloam Laguna loam, light-textured phase Montezuma clay adobe Goldridge loam Muck and peat Rough mountain land Rough broken land Riverwash I I I I I I II III III II I I VI III I I I I III III III VI VI I I VI VI III VI I I III VI I. VII VII VII Factors, per cent 100 100 100 100 100 100 85 60 60 100 100 65 60 95 95 100 100 50 65 65 50 50 100 100 50 40 70 100 100 70 70 100 70 100 100 85 60 65 100 100 100 70 90 65 85 85 60 85 65 85 85 85 65 60 85 55 60 100 85 100 60 100 100 60 100 100 100 100 70 100 100 100 95 95 100 100 100 90 90 80 100 100 100 100 90 100 100 90 100 55 55 100 80 Index per cent 100 70 100 70 85 Grade Remarks Includes areas of variable texture An overwash on Pinole Younger than typical of series May contain gravel Includes areas of variable char- acter Younger than typical of series Free from gravel 3 to 4 ft. deep; erosive Often somewhat eroded Drainage somewhat restricted Drainage restricted Texture variable Very compact subsoil Compact subsoil; not typical of Rolling; slightly eroded; not typical of series About 3 ft. deep Drainage restricted Drainage somewhat restricted; not typical of series Drainage restricted About V/2 ft. deep; rather steep; difficult to cultivate About 2 ft. deep; eroded Drainage restricted; low in hu- mus; subsoil heavier than typical of series 3 to 4 ft. deep Infertile; may have gravelly subsoil Infertile 2 to 6 ft. to substratum Low in humus Poorly drained Nonarable Nonarable Nonagricultural 58 University of California — Experiment Station 19. GILROY AREA The Gilroy area lies in the southern part of Santa Clara County, and comprises the upper end of Santa Clara Valley and the bordering foot- hills and mountains. The climate of the area is characterized by a long, rainless growing season, with most of the annual precipitation occurring during the three winter months. The rainfall averages about 20 inches a year on the valley floor, but increases to 30 or more inches in the sur- rounding mountains. The residual soils (group VI) occur in the mountains and hills and are derived from the disintegration of sedimentary rocks with intrusions of basic igneous rocks and serpentine. The soils of this group from sedi- mentary material are mapped as Altamont, Arnold, and Goldridge, and those from basic igneous rocks as Aiken, Olympic, and Climax. In group III the soils having distinct development of profiles are the Pinole, Antioch, Corning, Rincon, San Ysidro, and Montezuma. The Pleasanton of this area is somewhat younger than typical and is placed in group II. The recent alluvial soils (group I) of the area are placed in the Yolo, Vina, Conejo, Honcut, Dublin, and Laguna series. Irrigation water is available from wells for most of the soils of group I, which are exten- sively used for a wide variety of crops, including deciduous fruits, truck, and seeds. Prunes are the principal crops of the area. The Pinole and Pleasanton are used particularly for prunes and grapes. Some orchards are grown on the residual soils, but they are used mostly for grain hay and pasture. Except locally, alkali and poor drainage are not serious problems in this area. Table 26 shows the soil group, index rating, and grade of the soils found in the Soil Survey of the Gilroy Area. 25 This survey covers 199,040 acres, of which more than half is nonarable on account of topography. Of the remainder, 18,560 acres are in grade 1 ; 17,152 acres in grade 2 ; and 42,048 acres in grade 3. The location of the grades of soil in the Gilroy area may be found in area 19 on map 3. 25 Cosby, S. W., and E. B. Watson. Soil survey of the Gilrov area, California. U. S. Dept. Agr. Bur. Soils, Field Oper. 1923:599-642. 1927. Bul. 599] A Rating of California Soils 59 20. GRASS VALLEY AREA The Grass Valley area is situated in the foothills east of the Sacramento Valley and covers the western third of Nevada County. The region is made up of rolling hills and ridges, with practically no level land. Eleva- tions range from about 300 feet to a maximum of about 4,000 feet. The climate varies with the altitude. Precipitation increases from about 20 TABLE 27 Grass Valley Area : Eating of Soils in Accordance with the Storie Index Soil type Aiken stony clay loam Aiken clay loam Sierra clay loam Sierra clay loam, shallow light- textured phase Holland fine sandy loam Holland fine sandy loam, shal- low phase Sites clay loam Sites stony loam Olympic stony clay loam Honcut silty clay loam Corning gravelly clay loam Rough broken and stony land Placer diggings Riverwash Soil group Factors, per cent Index per cent Grade A B C VI 40 60 100 24 4 VI 70 85 90 54 3 VI 70 85 90 54 3 VI 50 100 90 45 3 VI 70 100 100 70 2 VI 40 80 100 32 4 VI 70 85 90 54 3 VI 30 70 90 19 5 VI 60 60 90 32 4 I 95 90 90 77 2 III 60 55 100 33 4 VII 5 6 VII 2 6 VII 1 6 Remarks Av. depth V/i ft. ; widely variable character; rock outcrop Slightly acid; varies consider- ably 3 to 5 ft. deep; varies consider- ably 4 to 6 ft. deep Shallow; rock outcrop 6 ft. deep or more; erosive Shallow ; eroded Av. 3 ft. deep; erosion active Includes all recent alluvial soils of the area Somewhat variable Nonarable Eroded lands left from mining; nonarable Nonagricultural inches at the lower elevation to over 70 inches at the higher elevation, with considerable snow in the higher mountains. With the exception of small widely scattered areas of Honcut (group I) and Corning (group III) soils, all of the soils of the area are primary (group VI) , having been derived from the weathering of the underlying rocks. The Aiken and Olympic series are derived from basic igneous rocks, and the Holland and Sierra from granites, while the Sites is de- rived from sedimentary rocks. Many of the soils are stony and shallow. A small proportion of the area is in cultivation, stock raising being the principal agricultural occupation. Fruit, largely pears, is grown to a limited extent in favored localities. Considerably more of the area may become fruit land under irrigation. 60 University of California — Experiment Station Table 27 shows the soil group, index rating, and grade for each soil type found in the Soil Survey of the Grass Valley Area, 26 together with brief data on depth, stoniness, etc. This survey covers 280,960 acres. There are no grade-1 soils and only 2,752 acres of grade-2 soils ; 90,816 acres are in grade 3. The location of the soil grades in the Grass Valley area may be found in area 20 on map 1. 26 Watson, E. B., and J. B. Hammon. Soil snrvev of the Grass Valley area, Cali- fornia. U. S. Dept. Agr. Bur. Soils, Field Oper. 1918:1-40. 1921. Bui* 599] A Rating of California Soils 61 TABLE 28 Healdsburg Area : Eating of Soils in Accordance with the Storie Index Soil type Soil group Factors, per cent Index per cent Grade Remarks Aiken loam Aiken loam, stony variation. Olympic stony loam Olympic loam Olympic clay loam Olympic clay loam, dark heavy phase Sites gravelly loam. Altamont stony silty clay loam Altamont gravelly fine sandy loam Altamont silty clay loam. Butte loam Goldridge fine sandy loam.. Fresno gravelly fine sandy loam Fresno gravelly fine sandy loam, eroded phase Fresno loam.. Madera loam. Corning gravelly loam Corning loam Pleasanton gravelly sandy loam Pinole gravelly loam VI VI VI VI VI VI VI VI VI VI VI VI V V V V III III II III Honcut gravelly loam Yolo gravelly loam Yolo gravelly loam, stream- bottom phase Yolo fine sandy loam Yolo fine sandy loam, stream bottom phase Yolo loam Yolo loam, stream-bottom phase Yolo silty loam Yolo silt loam, stream-bottom phase Yolo silty clay loam Yolo silty clay loam, stream- bottom phase 50 50 40 40 40 60 60 25 60 50 30 80 40 40 40 40 60 60 100 100 100 100 100 100 100 100 100 100 100 100 70 70 100 85 85 80 70 90 100 100 70 70 100 100 70 100 70 70 100 100 100 100 100 100 90 00 90 90 80 90 90 100 90 100 100 90 70 90 50 90 100 90 100 100 90 90 100 90 100 95 100 70 90 100 90 100 72 Av. 1Y2 ft. ; erosion active Large content of stones Erosion active 10 to 36 in. deep; erosion active 10 to 36 in. deep; erosive 18 in. to 6 ft. deep; more typical of Climax 4J/£ to over 6 ft. deep; loam with few cobbles ; erosive Very shallow; stony 2 to 4 ft. deep; gravel not ex- cessive Depth and topography variable; erosive Shallow; low in humus; infertile and erosive 3 to 8 ft. deep; erosive Gray clay layers at substratum ; not typical of series Eroded and hilly; not typical of series Gray clay layers at substratum ; not typical of series Not typical of series; depth and character of substratum var- iable Eroded Gravel content variable Gravel content varies; erosion active in places Loam with some gravel Some danger of overflow Drainage variable Some danger of overflow Some danger of overflow Subject to occasional overflow Few areas of restricted drainage Drainage restricted 62 University of California — Experiment Station TABLE 28 — Healdsburg Area — {Concluded) Soil type Soil group Factors, per cent Index per cent Grade Remarks A B C II II I I I I VII VII 90 90 100 100 100 100 70 100 100 100 85 70 100 85 100 60 100 70 63 77 100 60 85 49 9 1 2 2 1 2 1 3 6 6 Dublin loam, light phase Overwash on Goldridge bedrock Rough mountainous land Nonarable 21. HEALDSBURG AREA The Healdsburg area is located in central Sonoma County, and includes the lower Russian River Valley, the Santa Rosa plain, and surrounding foothills. This region is protected by hills which provide an equable climate of moderate summer and winter temperatures, and moderate rainfall. Elevations within the area range from less than 100 feet to more than 2,000 feet. The residual soils (group VI), which occupy the hill areas, are the Aiken and Olympic series from basic igneous rocks ; the Sites, Altamont, and Goldridge from sedimentary rocks ; and the Butte from tuffaceous material. The Fresno and Madera series in this area are group-V soils, having a consolidated substratum rather than the hardpan typical of these series in other areas. The Corning and Pinole series are in group III and occupy slightly elevated terraces. The Pleasanton and Tehama series are group-II soils. The recent alluvial soils of group I are included in the Honcut, Yolo, and Dublin series. Some of these soils are poorly drained. The area is climatically suited for a wide range of crops, including deciduous fruits, grapes, berries, and truck crops. The area is not irri- gated. The group-VI soils, with the exception of the Goldridge, are de- voted largely to grain and pasture. The group-V soils are poorly drained and are not suited for most crops, whereas the group-Ill soils are exten- sively planted to fruits and grapes. The major part of the Gravenstein apples of this state are produced on the Goldridge and Pinole soils of this area. The more recent soils of groups I and II produce not only fruit, of which the larger acreage is prunes, but most of the annual crops of the area. Table 28 shows the soil group, index rating, and grade of the several Buu 599] A Rating of California Soils 63 soil types found in the Soil Survey of the Healdsburg Area. 27 This sur- vey covers 222,720 acres, of which about one-third is rough mountainous land. Of the remainder, 28,416 acres are in grade 1; 37,980 acres in grade 2 ; and 28,416 acres in grade 3. The location of the grades of soil in the Healdsburg area may be found in area 21 on map 3. 2 7 Watson, E. B., et al. Soil survey of the Healdsburg area, California. U. S. Dept. Agr. Bur. Soils, Field Oper. 1915:1-59. 1917. (Out of print.) 64 University of California — Experiment Station TABLE 29 Hollister Area : Eating of Soils in Accordance with the Storie Index Soil type Soil group Factors, per cent Index per cent Grade Remarks Yolo sandy loam Yolo fine sandy loam Yolo fine sandy loam, porous subsoil phase Yolo gravelly loam Yolo silt loam Yolo silty clay loam Yolo clay adobe Antiochloam Montezuma clay adobe Montezuma stony clay adobe alluvial-fan phase Rinconloam Rincon loam, light-textured phase Pleasanton gravelly sandy loam Holland sandy loam Altamont sandy loam Altamontloam Altamont clay loam Hanford sandy loam Chinoloam Conejo gravelly clay loam Capay silt loam Capay silty clay loam Dublin finesandy loam Dublin silty clay loam Dublin clay adobe Riverwash Rough mountainous land Rough broken land I I I I III III II III II II VI VI VI VI I I I III III I I I VII VII VII 100 100 100 100 100 100 100 60 70 55 95 85 60 50 50 50 100 100 100 75 75 100 100 100 95 100 100 70 100 90 60 100 60 35 100 too 65 95 95 10(1 85 95 100 55 10(1 100 95 60 100 100 55 100 100 100 90 90 100 100 100 100 100 100 90 90 100 60 100 50 50 75 100 95 100 55 70 100 90 54 54 42 Subsoil texture varies somewhat Friable; deep Coarse sand and gravel subsoil ; very leachy Varying quantities of gravel Deep ; friable Drainage restricted 3 to %Yi ft. to substratum Not typical of series Heavy subsoils ; often contains gravel Somewhat younger than typical of series 2 to %Yi ft. deep; erosion may be active ItoV/i ft. deep; erosive 2 to Z x /i ft. deep; erosive Friable; deep Poorly drained Hanford As mapped contains soils of other series Fertility low; variable amount of alkali Variable amount of alkali; fer- tility low Drainage restricted; may con- tain alkali May contain poorly drained Drainage restricted; may con- tain alkali Nonagricultural Nonarable Nonarable 22. HOLLISTER AREA The Hollister area is located in northern San Benito County. It includes the southern end of Santa Clara Valley, San Benito Valley, and adjacent hill lands. This area is surrounded by mountains, and although only a few miles from the coast, is protected from the modifying influences of the ocean. The summers are warm and dry, and the winters mild. The average annual rainfall at Hollister is about 13 inches. Bul. 599] A Rating of California Soils 65 The mountainous and hilly areas are composed of the residual soils (group VI) of the Holland series, derived from granite, and the Alta- mont series, from sedimentary rock. The older alluvial soils (group III) occupying elevated benches or terraces, are shown as the Antioch, Monte- zuma, and Capay series. One type of the Montezuma series is younger than typical (group II), and one type of the Bincon is older than typi- cal (group III). Soils of group II are represented by the Pleasanton series. The Capay series contains considerable alkali. The group-I soils are mapped as Yolo, Hanford, Chino, and Dublin series. The last two series are poorly drained and contain alkali in places. The valley soils that are not affected with alkali and have good drain- age are devoted to a wide range of crops, including deciduous fruits, truck, grain, and hay. The alkaline and poorly drained areas are devoted to pasture. The hill lands, where suitable for cultivation, are devoted principally to grain hay and pasture. Many of the orchards and truck lands are irrigated, the water being pumped from wells. Table 29 shows the soil group, index rating, and grade of each soil type in the Soil Survey of the Hollister Area. 28 This survey covers 192,- 640 acres, of which nearly one-third is rough mountainous and broken land. Of the remainder, 34,496 acres are in grade 1 ; 4,160 acres in grade 2 ; and 86,080 acres in grade 3. The location of the grades of soil in the Hollister area may be found in area 22 on map 3. 28 Cosby, Stanley W., and E. B. Watson. Soil survey of the Hollister area, Cali- fornia. U. S. Dept. Agr. Bur. Soils, Field Oper. 1923:643-81. 1927. 66 University of California — Experiment Station TABLE 30 Honey Lake Area : Eating of Soils in Accordance with the Storie Index Soil type Holland coarse sandy loam.. Holland coarse sandy loam, rock-outcrop* Holland coarse sandy loam, dark-colored phase Olympic stony loam Johnstonville coarse sand Johnstonville coarse sand, loamy phase Johnstonville sandy loam Johnstonville sandy loam, poorly drained phase Standish stony sandy loam. Standish gravelly sandy loam Standish sand Standish sandy loam Standish sandy loam (S) Standish sandy loam (B) Standish loam Standish loam (S) Standish loam (B) Standish clay loam (S) Standish clay loam (B) Standish clay loam (D) Lahontan sand (S) Lahontansand(B) Lahontan sand (D) Lahontan fine sandy loam (S) Lahontan fine sandy loam (B) Lahontan fine sandy loam (D) Lahontan loam (S) Lahontan loam (B) Lahontan loam (D) Lahontan silty clay loam Lahontan silty clay loam (B). Lahontan silty clay loam (D) Lahontan clay Lahontan clay, dark-colored phase Tuscan gravelly loam Churchill stony loam Churchill sandy loam Churchill loam Churchill loam (B) Churchill loam (D) Soil group VI VI VI VI II III III III III III III III III III III III III II II II II II II II II II II II II II II V IV IV IV IV IV Factors, per cent 60 70 85 80 80 80 90 95 95 70 70 60 95 95 95 100 100 100 85 85 85 60 60 60 100 100 100 100 100 100 90 90 90 50 50 70 70 95 100 100 100 100 90 100 90 60 Index per Grade Remarks Av. depth 3 ft. Frequent rock outcrop and ir- regular topography Drainage poor; not typical of series Av. depth \ l /2 ft. ; variable Leachy and wind-blown Leachy; may contain hardpan May have hardpan ; eroded Poorly drained; not typical of series Eroded; depth variable Stratified Stratified Subsoil variable Spotted alkali Strong alkali Stratified Spotted alkali Strong alkali Spotted alkali ; not typical of Strong alkali Very strong alkali Spotted alkali; drainage poor Strong alkali Very strong alkali Subsoil stratified; spotted alkali Strong alkali Very strong alkali Usually friable; may have hard- pan Strong alkali Very strong alkali Texture and depth variable; spotted alkali Strong alkali Very strong alkali Nonagricultural ; slick spots Badly waterlogged Shallow; eroded Shallow; stony ; infertile Shallow; infertile Texture variable; infertile; spotted alkali Strong alkali Very strong alkali * Areas where the soil survey indicates, by symbols, the presence of stone or rock. Bul, 599] A Rating of California Soils TABLE 30 — Honey Lake Area — (Concluded) 67 Soil type Carson loam Carson loam (B) Carson loam (D) Carson clay loam Carson clay loam (B) Carson clay loam (D) Carson clay adobe Carson clay adobe (B) Carson clay adobe (D) Buntingville sandy loam Buntingville sandy loam (B).. Buntingville sandy loam (D) Buntingville loam Buntingville clay loam Hanford stony sandy loam Hanford gravelly sandy loam Hanford coarse sand Hanford sandy loam Foster sandy loam Foster sandy loam, dark- colored phase Stacy gravelly sandy loam...... Stacy gravelly sandy loam, stone symbols* Stacy loam Stacy loam (B) Stacy loam (D) Preston sand Preston sand, shallow phase . Preston clay adobe Rough stony land Soil group VI Factors, per cent 90 90 90 90 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 95 60 60 95 95 95 100 85 65 65 40 95 95 95 65 20 100 100 100 20 20 50 40 10 100 60 10 Index per 32 Grade Remarks May contain hardpan; more compact than typical for series Strong alkali; drainage poor Very strong alkali ; drainage poor Drainage poor; usually alkaline; more compact than typical for series Strong alkali; drainage poor Very strong alkali Very sticky; overflowed; not typical of series Strong alkali Very strong alkali Friable; drainage fair; slight alkali Strong alkali Very strong alkali Drainage poor Drainage poor Excessive stones; low in humus Coarse material; low in humus Fertility low ; eroded Coarse and leachy ; low in humus Drainage fair May be swampy Leachy ; profile variable Very stony Friable ; slight alkali Strong alkali Very strong alkali Wind-blown material Rests on Lahontan beds Strong alkali Nonarable Areas where the soil survey indicates, by symbols, the presence of stone or rock. 23. HONEY LAKE AREA The Honey Lake area is situated in the southeastern part of Lassen County. It comprises that part of Honey Lake Valley within California, small areas of adjoining hilly and mountainous land, and a part of Long Valley. The Honey Lake Valley is on the desert side of the Sierra Nevada in the Great Basin. Honey Lake, which occupies a central position in this survey, is a shallow alkaline lake, a remnant of the ancient Lake Lahon- tan. The valley lies at an elevation of more than 4,000 feet in a region of short, dry summers, and cold, dry winters. The average annual precipi- tation is approximately 15 inches, part of which comes as snow. 68 University of California — Experiment Station The residual soils (group VI) of this area are the Holland and Olym- pic series, the former from granite and the latter from basic igneous material. The Tuscan series is in group V, and the Churchill, occupying high bench lands, is a group-IV soil. A slightly younger group includes those having consolidated subsoils of lake sediments mapped as Standish (group III). These soils usually contain alkali. The Carson, Lahontan, Johnstonville, and Buntingville series represent soils having moderate compaction and accumulated clay in the subsoil (group II). These may also contain alkali. The recent deposits (group I) include the Hanford, Foster, Stacy, and Preston series. The Preston soils are wind-blown, and the Stacy soils are highly alkaline. The rigid climate and the alkali of the region restrict the agricultural use of this valley. Alfalfa is grown where irrigation water is available and is used to supplement the native grass pasture during the winter. Stock raising is the principal agricultural activity. Table 30 shows the soil group, index rating, and grade for each soil in the Soil Survey of the Honey Lake Area, 29 together with brief remarks on alkali, drainage, and other modifying features. In this table the same alkali designations are used as were used in the soil-survey report, namely, S indicating alkali in spots ; B indicating concentrations of 200 to 500 parts per 100,000 ; and D, indicating concenrations of over 500 parts per 100,000. This survey covers 338,560 acres, but data are not available on the areal distribution of alkali, so that the areas included in the several grades were not computed. The location of the grades of soil in the Honey Lake area may be found in area 23 on map 1. 29 Guernsey, J. E., et al. Soil survey of the Honey Lake area, California. U. S. Dept. Agr. Bur. Soils, Field Oper. 1915:1-64. 1917. Bul, 599] A Rating of California Soils 69 TABLE 31 King City Area: Eating of Soils in Accordance with the Storie Index Soil type Salinas clay Salinas clay loam Salinas loam Salinas loam, gravelly phase... Salinas very fine sandy loam... Salinas finesandy loam Greenfield finesandy loam Greenfield fine sandy loam, gravelly phase Greenfield sand Greenfield sand, gravelly phase Lockwood gravelly loam Lockwood gravelly loam, silty phase Lockwood gravelly sandy loam Lockwood gravelly sandy loam, light-textured phase ... Hanford fine sand Hanford very fine sandy loam Metz silty clay loam Metz very finesandy loam Metz very fine sandy loam, heavy phase Metz fine sand Rincon finesandy loam Soil group Rincon fine sandy loam, heavy phase Rincon loam Rincon clay Yolo silty clay loam Yolo clay Yolo finesandy loam Yolo finesandy loam, gravelly phase Yolo fine sandy loam, light- textured phase Hames fine sandy loam Hames fine sandy loam, grav- elly phase Hames fine sandy loam, friable-subsoil phase Hames sandy loam Hames sandy loam, gravelly phase II II II II II II I I I I III III III III I I I I I I III III III III I I III III II III III Factors, per cent 95 95 95 95 95 95 100 100 100 100 70 70 70 70 100 100 100 100 100 100 65 65 65 65 100 100 100 100 100 75 75 SO 70 85 100 70 100 100 100 70 60 55 70 70 65 65 65 100 90 100 100 65 100 90 100 50 100 70 95 100 70 100 95 65 Index per cent 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 30 90 90 100 80 100 100 100 80 100 100 100 100 67 81 95 67 95 95 100 70 60 55 49 46 46 65 100 90 100 100 20 59 53 59 33 72 60 100 70 53 Grade Remarks Somewhat leachy Contains considerable gravel Often very gravelly in subsoil A somewhat younger soil than typical Overflow Slightly eroded; approaches Huerhuero in profile Heavy loam or clay loam ; slightly eroded; approaches Huerhuero in profile Approaches Huerhuero in profile Approaches Huerhuero in profile Occasional overflow Gravel content varies consider- ably Sandy loam, gravelly subsoil Not typical of series Slightly eroded 70 University of California — Experiment Station TABLE 31— King City Area— (Concluded) Soil type Hames sandy loam, friable- subsoil phase Hames sandy loam, heavy phase Hames sandy loam, hardpan phase Santa Lucia clay Santa Lucia clay, gravelly phase Santa Lucia loam Santa Lucia loam, gravelly phase Santa Lucia loam, light-tex- tured phase Kettleman loam Kettleman loam, gravelly phase Diablo gravelly loam Diablo clay Garey sandy loam Gareysand Garey sand, loamy phase Docasloam Docas clay loam Barron gravelly sandy loam Ramona sandy loam Holland sandy loam Holland clay Dublin clay Riverwash Dunesand Rough broken and stony land Soil group II III IV VI VI VI VI VI VI VI VI VI II II II II II II III VI VI I VII VII VII Factors, per cent 35 70 SO 65 60 40 100 95 85 85 70 65 100 70 100 100 70 70 90 60 70 100 85 65 95 95 50 100 90 100 100 100 100 100 90 80 90 90 100 Index per cent Grade Remarks Not typical of series Loam or clay loam Hardpan at 40 to 60 in.; eroded; not typical of series 2 ft. deep 12 to 30 in. deep 12 to 30 in. deep Not typical of series Bedrock 24 to 60 in. Bedrock 18 to 40 in. ; erosive Av. depth 3 ft. ; considerable var- iation in texture; eroded About 4 ft. deep; erosion active Hummocky ; leachy Hummocky ; leachy Erosive Erosive Eroded; considerable gravel in subsoil Not typical of series Erosive Not typical of series Drainage poor Nonagricultural Nonagricultural Nonarable 24. KING CITY AREA The King City area is in Monterej^ County and includes that portion of the Salinas Valley and adjacent territory lying south of a line about 7 miles north of King City. Included in this area are a number of parallel valleys, of which the Salinas Valley is the largest. Among the more im- portant of the smaller valleys are Lewis Creek, Peach Tree, Priest, Hames, San Antonio River, and a portion of Nacimiento River. There is considerable variation in rainfall in this area, but the average is less than 20 inches annually. The group-VI soils consist of the Santa Lucia, Kettleman, and Diablo series, derived from sedimentary rocks, and the Holland, derived mainly Bul. 599] a Rating of California Soils 71 from granitic rocks. The hardpan soil (group IV) has been mapped as a phase of Hames sandy loam. The group-Ill soils consist of the Lock- wood, Rincon, Hames, and Ramonaseries. The group-II soils consist of the Salinas, Garey, Docas, and Barron, and the friable subsoil phases of the Hames series. The recent alluvial materials, group I, consist of the Greenfield, Hanford, Metz, Yolo, and Dublin series. All of the intensive agriculture, consisting of truck crops, beans, alfalfa, and most general farm crops, is conducted on the group-I and group-II soils. Grain and hay are grown on the older terrace soils, and dairying and cattle raising are important industries. Table 31 gives the soil group, index rating, and grade of the several soil types found in the Soil Survey of the King City Area. 30 This survey covers 769,280 acres, of which more than half is of little or no agricul- tural use, being either rough mountainous areas or riverwash. Of the remaining area, 37,632 acres are in grade 1 ; 50,112 acres in grade 2 ; and 102,720 acres in grade 3. The location of the grades of soil in the King City area may be found in area 24 on map 3. 30 Carpenter, E. J., A. E. Kocher, and F. O. Youngs. Soil survey of the King City area, California. U. S. Dept. Agr. Bur. Chem. and Soils, Ser. 1924, Eept. 24:1-63. 72 University op California — Experiment Station TABLE 32 Lancaster Area : Eating of Soils in Accordance with the Storie Index Soil type Holland sandy loam Adelanto gravelly sand, roll- ing phase Adelanto sand Adelanto loamy sand Adelanto loamy sand, rolling phase Adelanto sandy loam Ramona loamy sand Ramona loamy sand, rolling phase Ramona sandy loam Hesperiasand Hesperiasand, hummocky phase Hesperia loamy sand Hesperia loamy sand, hum- mocky phase Hesperia loamy sand, dark- colored phase Hesperia sandy loam Rosamond sand Rosamond sand (S) Rosamond sand (M) Rosamond sand (A) Rosamond sand, hummocky phase Rosamond sand, well-drained phase Rosamond fine sandy loam Rosamond fine sandy loam (S) Rosamond fine sandy loam (M) Rosamond fine sandy loam (A) Rosamond fine sandy loam, hummocky phase Rosamond loam Rosamond loam (S) Rosamond loam (M) Rosamond loam (A) Rosamond silt loam Rosamond silt loam (S) Rosamond silt loam (M) Rosamond silt loam (A) Rosamond clay loam Rosamond clay loam (S) Rosamond clay loam (M) Rosamond clay loam (A) Sunrise sand Sunrise fine sandy loam Sunrise fine sandy loam (S) Soil group VI II II III III III II II II I I I II II II II II II II II II II II II II II II II II II IV III III Factors, per cent 95 95 95 90 90 90 90 90 95 95 60 100 100 100 100 100 100 100 100 100 100 100 100 100 85 85 85 85 60 100 100 90 100 100 100 100 50 100 30 100 50 100 100 90 50 100 90 76 50 85 76 50 10 85 76 50 10 85 76 50 10 100 85 72 Index per cent Grade 43 Remarks 28 to 60 in. deep; eroded Eroded ; not typical of Not typical of series Badly cut up with gullies Badly eroded Incoherent sand ; low in humus Sand hummocks Hummocks Differs from typical only in color Drainage restricted Slight alkali Moderate alkali Strong alkali Topography rough Better drained than typical Slight alkali Moderate alkali Strong alkali Hummocks Often very compact; drainage usually deficient Slight alkali Moderate alkali Strong alkali Drainage usually deficient Slight alkali Moderate alkali Strong alkali Drainage poor Slight alkali Moderate alkali Strong alkali Hardpanat20to30in. Hardpan not well developed ; drainage restricted Slight alkali Bul. 599] A Rating of California Soils TABLE 32 — Lancaster Area — (Continued) 73 Soil type Soil group Factors, per cent Index Grade Remarks A B C per cent Sunrise fine sandy loam (M) Sunrise fine sandy loam (A) III III II IV IV IV IV IV IV IV IV IV II II II II II II II II II II II II II II II II II II II II II II II II 60 60 60 25 25 25 25 25 35 35 35 35 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 1 90 90 90 90 90 90 100 100 100 60 100 100 100 100 100 100 100 100 60 60 60 60 60 60 60 60 95 95 95 95 95 95 95 95 100 100 100 100 70 70 70 70 50 10 85 100 100 80 60 10 85 80 50 10 80 64 50 9 85 68 50 9 50 44 26 5 50 44 26 5 50 38 30 5 50 40 30 5 30 6 51 15 25 20 15 3 30 28 18 4 43 35 27 5 46 37 27 5 43 38 22 4 43 38 22 4 45 38 27 5 32 25 19 3 4 6 3 5 4 4 5 6 4 4 5 6 3 4 4 6 3 4 4 6 3 4 4 6 3 4 4 6 3 4 4 6 4 4 5 6 Moderate alkali Strong alkali Domino sand drainage restricted Hardpan at 14 to 30 in. Domino fine sandy loam Domino fine sandy loam (S).... Domino fine sandy loam (M).... Domino fine sandy loam (A).... Domino fine sandy loam, heavy phase Hardpan at 10 to 30 in. Slight alkali Moderate alkali Strong alkali Hardpan softer than other type; Domino fine sandy loam, loam texture Slight alkali Domino fine sandy loam, Moderate alkali Domino fine sandy loam, Strong alkali Drainage poor Pond sand (S) Slight alkali Pond sand (M) Moderate alkali Strong alkali Pond sand, hummocky phase.. Pond sand, hummocky phase (S) Hummocky Slight alkali Pond sand, hummocky phase (M) Moderate alkali Pond sand, hummocky phase (A) Strong alkali Drainage poor; puddles badly Slight alkali Moderate alkali Pond sandy loam (A) Strong alkali Pond sandy loam, dark- Drainage poor Pond sandy loam, dark- Slight alkali Pond sandy loam, dark- Moderate alkali Pond sandy loam, dark- Strong alkali Pond fine sandy loam Pond fine sandy loam (S) Pond fine sandy loam (M) Pond fine sandy loam (A) Pond fine sandy loam, hum- Drainage poor Slight alkali Moderate alkali Strong alkali Wind-blown; drainage poor Pond fine sandy loam, hum- Slight alkali Pond fine sandy loam, hum- Moderate alkali Pond fine sandy loam, hum- Strong alkali 74 University of California — Experiment Station TABLE 32 — Lancaster Area — (Concluded) Soil type Pond loam (M) Pond loam (A) Pond loam, well-drained phase Pond clay, dark-colored phase Cajonsand Cajon fine sandy loam Tujunga gravelly sand Tujungasand Hanford gravelly sandy loam.. Chino finesandy loam Riverwash Rough mountainous land Rough broken and stony land Playa deposits Dunesand Soil group II II III II I I I I I II VII VII VII VII VII Factors, per cent 90 90 60 90 100 100 100 100 100 95 100 100 100 50 70 100 25 60 70 100 25 3 90 10 90 90 80 80 100 80 Index per cent Grade Remarks Moderate alkali ; drainage poor Strong alkali Not typical of series High in alkali; poorly drained Low in humus; contains loamy sand Low in humus Leachy ; overflow occasionally Gravelly in places ; leachy Drainage somewhat restricted Nonagricultural Nonarable Nonarable Nonagricultural Nonagricultural 25. LANCASTER AREA The Lancaster area is situated in the southwestern part of the Mojave Desert region in that portion known as the Antelope Valley. It lies mainly in northern Los Angeles County. This is a region of low rainfall and long hot summers, but because of its elevation (about 2,500 feet) the winters are relatively cold. The average annual rainfall is less than 10 inches. With the exception of a limited acreage of Holland sandy loam, a group-VI soil from granites, all of the soils mapped in this area are alluvial. Some of them, however, occupy old terraces and contain hard- pans. These group-IV soils are included in the Sunrise and Domino series. Two soils having compact subsoils (group III) have been in- cluded as phases of the Adelanto and Pond series and the fine sandy loam of the Sunrise series. In group II are included the Ramona, Rosa- mond, and Chino series, as well as the more typical members of the Pond and Adelanto series and the silt loam of the Sunrise series. Representing the group-I soils are the Hesperia, Cajon, Hanford, and Tujunga series. It will be noted that included in the Sunrise series are soils having a wide range of profile development. Most of the soils of the area contain alkali, and the heavier-textured members are frequently rendered practically useless by excessive ac- cumulations of salts. Irrigation is required for practically all crops, and as the supply of water is limited, only the better soils are used for agricultural purposes. Late frosts make the production of fruits uncer- Bul. 599] A Rating of California Soils 75 tain over much of the area. Alfalfa hay is the most important crop in the Antelope Valley. Pears are grown successfully on the better, well- drained soils of the Hesperia, Cajon, and Adelanto series, where water is available. Table 32 gives the soil group, index rating, and grade for each soil type found in the Soil Survey of the Lancaster Area, 51 together with brief remarks on modifying factors. The soils containing alkali are rated according to the degree of concentration as slight (S), moderate (M), and strong (A). This survey covers 339,200 acres, but data are not available on the areal extent of the different degrees of alkali, and con- sequently the acreage included in each grade is not given. The location of the grades in the Lancaster area may be found in area 25 on map 4. 31 Carpenter, E. J., and Stanley W. Cosby. Soil survey of the Lancaster area, California. U. S. Dept. Agr. Bur. Soils, Field Oper. 1922:663-720. 1926. 76 University of California — Experiment Station TABLE 33 Livermore Area : Eating or Soils in Accordance with the Storie Index Soil type* Contra Costa sandy loam Diablo clay adobe Altamont clay loam Altamont clay adobe Vallecitos loam Vallecitos stony clay loam Vallecitos clay adobe Pleasanton sandy loam Pleasanton gravelly sandy loam Pleasanton loam Pleasanton gravelly clay loam Pleasanton clay adobe Mocho gravelly fine sandy loam Mocho sandy loam Mocho fine sandy loam Mocho loam Santa Rita loam Santa Rita silty clay loam Santa Rita clay adobe Livermore fine sandy loam Livermore silty fine sandy loam Livermore gravelly sandy loam Livermore loam Livermore clay loam Livermore clay Dublin loam Dublin clay loam Dublin clay loam adobe Dublin clay adobe Ulmar fine sandy loam Ulmarloam Danville clay loam adobe Tassajero clay loam Sunolloam Soil group Factors, per cent Index per cent Grade A B C VI 60 95 100 57 3 VI 70 70 100 49 3 VI 70 85 90 54 3 VI 70 70 90 44 3 VI 45 100 80 36 4 VI 65 60 40 16 5 VI 70 70 80 39 4 II 80 95 80 61 2 II 80 65 80 42 3 II 80 100 90 72 2 II 80 55 80 35 4 II 80 70 70 39 4 I 100 70 80 56 3 I 100 95 80 76 2 I 100 100 90 90 1 I 100 100 100 100 1 I 100 100 90 90 1 I 100 90 90 81 1 I 100 70 70 49 3 I 100 100 95 95 1 I 100 100 100 100 1 I 100 65 100 65 2 I 100 100 100 100 1 I 100 85 100 85 1 I 100 60 95 57 3 I 100 100 100 100 1 I 100 85 100 85 1 I 100 80 £0 72 2 I 100 70 80 56 3 V 50 100 60 30 4 V 30 100 60 18 5 I 100 85 100 85 1 I 100 85 100 85 1 II 90 90 100 81 1 Remarks Av.depth3Mto4ft. Av. depth 4 ft. ; eroded Av. depth 4 ft. ; eroded Av. depth iy 2 ft.; usually rough and steep Av. depth Z l A ft. ; very steep Deep and steep; eroded Broken topography Broken topography Subject to considerable subsoil variation Rough topography Rough and broken topography Gravelly subsoil Subsoil variable Occasionally gravel in subsoil Drainage slightly restricted Drainage slightly restricted Drainage poor; alkali in some areas Dissected with stream channels Friable Variable gravel content Friable Good drainage; friable Friable Drainage restricted; may con- tain alkali Av. depth to hardpan 4 ft. ; alkali Av. depth to hardpan 3 ft. ; alkali * The names given to some of the soil series in the older areas (Livermore, 1910) may not conform to later correlations and the soil ratings given in this table should not be confused with those for soils having similar names in other areas. 26. LIVERMORE AREA The Livermore area includes the major portion of the Livermore Valley and adjacent hills in Alameda and Contra Costa counties. This is an area of moderate rainfall, averaging about 15 inches. The summers are cool and the winters mild. The Contra Costa, Diablo, Altamont, and Vallecitos series are derived Bul, 599] A Rating of California Soils 77 from the weathering of sedimentary rocks (group VI). The Ulmar series has a hardpan substratum (group V). Group II includes the Pleasanton and Sunol series. The Mocho, Santa Rita, Dublin, Livermore, and Tassajero series are included in group I. Agriculture in the Livermore Valley is varied, with alfalfa, decidu- ous fruit, grapes, truck, and grain occupying the majority of the culti- vated areas. Irrigation is practiced to a limited extent only. Table 33 shows the soil group, index rating, and grade of each soil type found in the Soil Survey of the Livermore Area. 3,2 This survey covers an area of 155,520 acres, of which 12,416 acres are in grade 1 ; 31,552 acres in grade 2 ; and 102,528 acres in grade 3. The location of the grades of soil in the Livermore area may be found in area 26 on map 3. 32 Westover, H. L., and C. Van Duyne. Soil survey of the Livermore area, Cali- fornia. U. S. Dept. Agr. Bur. Soils, Field Oper. 1910:1657-716. (Out of print.) 78 University of California — Experiment Station TABLE 34 Lodi Area : Rating of Soils in Accordance with the Storie Index Soil type Soil group Ryde silty clay loam Sacramento silty clay loam. Sacramento loam Capay clay loam Capay clay adobe Stockton clay loam... Stockton clay adobe. Stockton clay adobe, deep phase Merced sandy loam Merced sandy loam, light- colored phase Columbia very fine sandy loam Hanford loamy sand Hanford sandy loam Hanford sandy loam, calcar- eous-subsoil phase Hanford sandy loam, poorly drained phase Honcut very fine sandy loam Bear Creek clay loam Bear Creek clay loam, gray phase Bear Creek clay adobe Greenfield sandy loam Greenfield gravelly sandy loam Wyman silt loam. . . Wyman clay loam. Wyman clay loam, poorly drained phase Wyman clay loam, shallow phase Wyman clay loam, calcareous subsoil phase I II II III III V V III III III I I I Factors, per cent 100 90 90 SO 50 50 80 50 50 too 100 100 100 100 100 90 90 100 85 70 85 70 70 95 95 100 80 95 95 95 100 85 85 70 95 65 100 85 85 85 85 50 50 80 100 100 30 100 80 100 100 60 70 100 Index per cent Grade 72 65 72 58 48 34 28 45 24 24 80 80 95 76 29 100 54 61 50 81 56 95 81 48 57 81 Remarks Highly organic; drainage fair Highly organic; drainage fair Highly organic; friable; drainage fair Consolidated substratum ; drainage fair Consolidated substratum ; drainage fair Consolidated substratum at 36 to 50 in. ; drainage poor Consolidated substratum at 36 to 50 in. Substratum at 50 to 72 in.; not entirely typical of series Drainage poor; alkali; hardpan Drainage poor; alkali; hardpan- like substratum Texture variable; subject to overflow Friable; often consolidated sub- stratum below 5 ft. Friable; often consolidated sub- stratum below 5 ft. Consolidated substratum at 30 to 50 in. Consolidated substratum at 3 to 5 ft. ; drainage poor Friable; deep Consolidated substratum at 30 to 50 in.; drainage somewhat restricted Consolidated substratum at 40 to 60 in. Consolidated substratum at 40 to 60 in. ; drainage poor Consolidatedsubstratum at 50 in. Gravelly substratum at 20 to 50 in. Consolidated substratum below 5 ft. Drainage poor; usually deep Consolidated substratum at 2 to 4 ft. Bul, 599] A Rating of California Soils TABLE 34— Lodi Area— (Concluded) 79 Soil type Soil group Factors, per cent Index per cent Grade A B C IV 20 100 100 20 4 IV 30 100 100 30 4 IV 20 100 60 12 5 II 80 95 100 76 2 II 80 95 60 46 3 IV 25 70 100 18 5 IV 25 70 100 18 5 V 20 70 100 14 5 V 10 70 100 7 6 VI 25 95 80 19 5 VI 25 70 90 16 5 VI 50 100 100 50 3 I 100 100 70 70 2 I 100 100 50 50 3 VII 1 6 Remarks Rocklynloam Rocklyn loam, deep phase Rocklyn loam, poorly drained phase Ramona sandy loam Ramona sandy loam, shallow phase Redding gravelly loam Redding gravelly loam, dark- colored phase Tuscan stony loam Tuscan stony loam, scabland phase Butte sandy loam Pentz clay adobe Whitney fine sandy loam Peat Peat, shallow phase Tailings Less than 2 ft. deep Considerable variation in sub- stratum Shallow; drainage poor Consolidated substratum at 2 to 4 ft. Hardpan at less than 30 in. Hardpan at less than 30 in. Very shallow and stony Very shallow and stony Less than 20 in. deep; erosive 15 to 30 in. deep; drainage re- stricted 3 ft. deep Organic; drainage poor Organic ; drainage poor Mining debris; nonagricultural 27. LODI AREA The Lodi area comprises essentially the northern half of San Joaquin County and a small portion of southern Sacramento County. It lies on the east side of the Great Valley and extends from the Sierra Nevada foothills on the east to the flat basin of the Mokelumne River delta on the west. The region is one of moderate rainfall, the mean annual pre- cipitation being about 20 inches. Temperatures are moderate both sum- mer and winter, although the summers are long and dry. The residual soils (group VI) of the Butte, Pentz, and Whitney series are found at the eastern edge of the area. The rolling terraces and ridges, which extend out from the foothills, are composed of the shallow stony soils of the Tuscan series (group V) and the hardpan soils of the Redding and Rocklyn series (group IV). On the flat valley plain are found the Capay and Merced series of group III, and associated with them are the group-V soils of the Stockton series. Adjoining these are the group-II soils of the Sacramento, Bear, Wyman, and Ramona series, and the group-I soils of the Columbia, Hanford, Honcut, and Green- field series. In the lower reaches of the area, in and adjacent to the sloughs and river channels of the delta, are the highly organic soils of the Ryde series and the organic peat soils, also group I. In this area 80 University of California — Experiment Station many of the secondary soils, including members of groups I, II, and III, are underlain by a hardpan substratum. Apparently the Mokelumne and tributary streams have laid down a deposit of these more recent soils over older hardpan material. In most cases this substratum is at a depth that does not particularly detract from the value of the overlying material, but in a few cases, such as the Merced, it is close enough to the surface to lower its usefulness. The agriculture of this area is extremely varied. The peat and organic soils are intensively farmed to truck erops, potatoes, asparagus, onions, etc. The recent alluvial soils are devoted largely to deciduous fruits and grapes. Grain and hay occupy large areas of the soils of intermediate value, and the rougher soils are used for pasture. Table 34 gives the soil group, index rating, and grade for each soil type found in the Soil Survey of the Lodi Area. 33 This survey covers approximately 350,000 acres, but as the report is not yet published, data are not available as to the areal distribution of the soil types. The location of the several grades of soil in the Lodi area may be found in area 27 on map 2. 33 Cosby, Stanley W., and E. J. Carpenter. Soil survey of the Lodi area, Cali- fornia. U. S. Dept. Agr. Bur. Chem. and Soils. (In press.) Bul. 599] A Rating of California Soils 81 TABLE 35 Los Angeles Area : Eating of Soils in Accordance with the Storie Index Soil type Altamont loam Altamont clay loam Altamont clay Altamont clay adobe Diablo clay adobe Holland sandy loam Holland sandy loam, coarse phase Holland loam Ramona sandy loam Ramona fine sandy loam Ramona loam Ramona loam (S) Ramona clay loam Ramona clay loam (S) Pleasanton loam Madera fine sandy loam Montezuma clay adobe Hanfordsand Hanford sand (S) Hanford sand (A) Hanford sandy loam Hanford sandy loam (S) Hanford sandy loam (A) Hanford sandy loam, coarse phase Hanford fine sandy loam Hanford fine sandy loam (S). Hanford fine sandy loam (A) Hanford loam Hanford clay loam Hanford clay loam (S) Tujungasand Tujunga fine sand Tujunga fine sand (S) Tujunga fine sandy loam Chino silt loam i Chino silt loam (S) Chino silt loam (A) Chino silt loam, light tex- tured*phase Chino silt loam, light tex- tured phase (S) Chino silt loam, light tex- tured phase (A) Chino clay loam Soil group VI VI VI VI VI VI VI VI II II II II II II II IV III I I I I I I I I I I I I I I I I I I I I I I Factors, per cent 55 60 60 60 60 50 50 50 85 85 85 85 85 85 85 30 80 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 95 95 95 95 95 95 95 100 85 60 60 70 95 90 100 95 100 100 100 85 85 100 100 70 60 95 95 95 90 100 100 100 100 85 85 60 65 65 100 100 100 100 100 100 100 85 100 100 100 80 100 85 90 90 90 90 80 100 90 90 100 100 80 40 100 90 40 90 100 75 30 100 100 60 90 50 40 90 90 80 40 40 100 Index per cent 55 51 36 29 42 43 38 45 73 77 77 68 72 65 77 30 56 54 48 24 95 86 38 81 100 75 30 100 85 51 54 33 90 76 Grade Remarks 1 to 5 ft. deep 1 to 6 ft. deep 1 to 6 ft. deep Av. depth 3 ft. ; eroded Av. depth 3 ft. V/i to 3 ft. deep; erosive \ X A to 3 ft. deep; erosive V/i ft. deep; erosive Erosive; subsoil may approach hardpan Erosive; low in humus; subsoil may be dense Slight alkali Slight alkali Similar to Ramona ; gravelly substratum About 3 ft. to hardpan Coarse texture, low moisture- holding capacity Slight alkali Strong alkali Slight alkali Strong alkali Low in humus Deep; friable Slight alkali Strong alkali Alkali-spotted Low in humus Subject to overflow; high water table Alkali-spotted Low in humus; occasional over- flow Drainage fair Slight alkali Strong alkali Fine sandy loam texture Slight alkali Strong alkali Friable 82 University of California — Experiment Station TABLE 35 — Los Angeles Area — {Concluded) Soil type Soil group Factors, per cent Index per cent Grade Remarks A B C Chino clay loam (S) I I I I I I I I I I I I I II VII VII VII VII 95 95 100 100 100 100 100 100 100 100 100 100 100 85 85 85 80 100 100 100 85 60 60 60 60 60 60 65 90 40 90 100 100 75 100 90 80 30 90 80 30 80 73 32 72 100 100 75 85 54 48 18 54 48 18 44 3 1 5 5 2 4 2 1 2 1 3 3 5 3 3 5 3 6 6 6 6 Slight alkali Yolo sandy loam Coarse texture; somewhat Yolo sandy loam, heavy phase gravelly Fine sandy loam texture Yolo loam (S) . Spotted alkali Dublin clay (S) Spotted alkali Dublin clay adobe (S) Coastal beach and dunesand... Nonagricultural 28. LOS ANGELES AREA The Los Angeles area is located in and around the City of Los Angeles and the area between the city and the ocean to the west and south. The soils of the Altamont and Diablo series, derived from sedimentary rocks, and the Holland series, derived from the granitic rocks (all of group VI) occupy the hills north and northwest of the city. The Madera (group IV), Montezuma (group III), and the Ramona, Pleasanton, and Oakley (group II) series, occupy elevated to slightly elevated alluvial fans or terraces. The group-I soils, comprising the Hanford, Tujunga, Chino, Yolo, and Dublin series, occupy flat alluvial fans and flood plains. Alkali is present in damaging quantities in some of the lower- lying soils. This is an area of extensive urban development and the major portion of the area may be considered as nonagricultural for this reason. Under such circumstances, the nature of the soil is of minor consideration. Field crops, grain, beans, beets, and truck are extensively grown on the recent alluvial soils and on the better-drained areas. Where water is available, citrus, walnuts, and deciduous fruits are grown on a wide variety of soils. For these crops climatic and other environmental fac- tors have had a greater influence than the inherent qualities of the soil. Table 35 gives the soil group, index rating, and grade for each soil Bul. 599] A Rating of California Soils 83 type found in the Soil Survey of the Los Angeles Area. 3 * A rating for the soils having alkali is shown ; S designates low alkali concentration, and A, high alkali concentration, and the values are calculated as 90 per cent and 40 per cent of that given for alkali-free conditions. This survey covers 360,320 acres, but data on the areal distribution of alkali are lacking, and urban development is of such local importance that the acreage for the different soil grades is not calculated. The location of the grades of soil in the Los Angeles area may be found in area 28 on map 4. 34 Nelson, J. W., et al. Soil survey of the Los Angeles area, California. U. S. Dept. Agr. Bur. Soils, Field Oper. 1916:1-78. 1919. 84 University of California — Experiment Station TABLE 36 Madera Area: Eating of Soils in Accordance with the Storie Index Soil type* Soil group Factors, per cent Index per cent Grade Remarks A B C I I I I I I I I I I I I I I I I I I IV I IV IV IV IV IV IV IV IV IV IV IV IV IV IV IV IV IV IV IV IV IV IV IV 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 50 100 50 50 50 50 50 40 40 40 40 40 30 30 30 30 30 50 50 30 50 40 25 40 25 60 '65 90 90 90 90 85 85 85 85 95 95 95 95 100 100 100 100 60 60 80 80 80 80 80 100 100 100 100 100 85 85 85 85 85 60 60 95 100 85 95 65 85 80 100 100 80 60 40 100 80 60 40 100 80 60 40 100 80 60 38 100 100 100 80 60 40 10 100 80 60 40 10 100 80 60 40 10 90 100 100 100 100 90 100 100 48 65 90 72 54 36 85 68 51 34 95 76 57 38 100 80 60 38 30 60 40 32 24 16 4 40 32 24 16 4 26 20 15 10 3 27 30 29 50 34 21 26 21 3 2 1 2 3 4 1 2 3 4 2 3 4 1 1 2 4 4 2 3 4 4 5 6 3 4 4 5 6 4 4 5 5 6 4 4 4 3 4 4 4 4 variable Hanford coarse sandy loam (B) Hanford coarse sandy loam (C) Hanford coarse sandy loam(D) Alkali slight Alkali moderate Alkali strong Hanford sandy loam (D) Alkali strong Hanford fine sandy loam (B).... Hanford fine sandy loam (C).... Hanford fine sandy loam (D).. Fresno sand Alkali slight Alkali moderate Alkali strong iable Fresno loamy coarse sand Fresno loamy coarse sand (B).. Fresno loamy coarse sand (C).. Fresno loamy coarse sand (D).. Fresno loamy coarse sand (E).. Fresno fine sandy loam Depth to hardpan variable; av. over 4 ft. Alkali slight Alkali moderate Alkali strong Alkali very strong Fresno fine sandy loam (B) Fresno fine sandy loam (C) Fresno finesandy loam (D) Fresno fine sandy loam (E) Fresno clay loam 4 ft. Alkali slight Alkali moderate Alkali strong Alkali very strong Fresno clay loam (B) Fresno clay loam (D) Fresno clay loam (E) hog wallows Madera finesandy loam San Joaquin gravelly sandy hog wallows smoother than typical hog wallows * Names given in some of the older areas (Madera, 1910) may not conform to later correlations and the rating values should not be confused with those for soils having similar names in other areas. Bul, 599] A Rating of California Soils TABLE 36 — Madera Area — (Concluded) 85 Soil type* Soil group Factors, per cent Index per cent Grade Remarks A B C Media coarse sandy loam VI VI VI VI VI VI VI II VII VII 40 60 60 60 40 50 70 90 70 95 100 70 95 85 70 70 90 90 90 90 70 70 85 60 25 51 54 38 27 30 42 38 5 4 3 3 4 4 4 3 4 6 6 Av. depth to bedrock 2 ft. ; rock outcrop ; coarse-textured Av. depth to bedrock 3 ft.; rock outcrop outcrop outcrop Av. depth to bedrock 2 ft. ; eroded series Nonarable Nonagricultural * Names given in some of the older areas (Madera, 1910) may not conform to later correlations and the rating values should not be confused with those for soils having similar names in other areas. 29. MADERA AREA The Madera area is located in the central part of the San Joaquin Valley and comprises the major part of the agricultural lands of Madera County. The area extends from the flat valley floor along the San Joaquin River on the west to and including a narrow band of the Sierra Nevada foothills on the east. This is a region of low rainfall, hot dry summers, and mild winters. The group-VI soils, which occupy the foothills, are mapped as the Media series, derived from feldspar, and the Daulton series, from granitic rocks. The hardpan soils, group IV, consist of the Madera and San Joaquin series on the higher terraces, and the Fresno series on the flatter areas. The Porterville series (group II) and the Hanford series (group I) are the slightly weathered and un weathered soils. Alkali on the Hanford, Porterville, and Fresno series restricts their value. Alfalfa, fruit, grapes, and general field crops are grown on the recent alluvial soils where the alkali is not too strong. Under favorable conditions similar crops are grown on the hardpan soils, and under less favorable conditions grain, hay, and pasture are the principal crops. Table 36 gives the soil group, index rating, and grade of the several types of soil found in the Soil Survey of the Madera Area. 35 The alkali designations used are the same as those used in the soil survey, namely, 35 Strahorn, A. T., et al. Soil survey of the Madera area, California. U. S. Dept. Agr. Bur. Soils, Field Oper. 1910:1717-53. (Out of print.) 86 University of California — Experiment Station B indicating 200 to 400 parts per 100,000 ; C indicating 400 to 600 parts per 100,000; D indicating 600 to 1,000 parts per 100,000; and E over 1,000 parts per 100,000. This survey covers 588,160 acres, but data are not available showing the areal distribution of the different degrees of alkali. The location of the different grades of soil in the Madera area may be found in area 29 on map 2. Bul, 599] A Rating of California Soils 87 TABLE 37 Marysville Area : Rating of Soils in Accordance with the Storie Index Soil type* Soil group Factors, per cent Index per cent Grade Remarks Sacramento fine sand Sacramento fine sandy loam. Sacramento silt loam Sacramento clay San Joaquin gravelly loam. San Joaquin fine sandy loam. San Joaquin sandy loam San Joaquin loam Alamo clay loam adobe Alamo clay adobe. Sutter sandy loam Sutter loam Sutter clay Sutter clay loam adobe. Gridley sandy loam Gridley loam Gridley silty clay loam.. Sierra loam Stockton clay adobe Feather loam Feather silt loam Marcuse clay loam Bear loam Honcut loam Marysville silt loam... Riverwash Rough stony land I I I IV IV IV IV IV IV I I I I III III IV VI V I I III I I IV VII VII 100 100 100 100 60 40 35 25 25 100 100 100 100 25 40 40 100 100 80 100 100 50 65 100 100 70 100 95 100 60 100 100 60 85 100 100 100 60 100 100 85 100 100 100 100 100 100 100 100 100 100 100 100 80 100 100 100 60 100 100 100 100 40 100 100 100 52 100 100 60 42 20 38 35 17 100 100 48 85 40 24 100 100 27 100 100 50 2 5 Variable; subject to overflow and poor drainage; not typical of series May be shallow or contain alkali ; not typical of series May be shallow or contain alkali ; not typical of series May contain alkali; not typical of series Hardpan usually below 6 ft. ; not typical of series Hardpan at 2 ft. or less Av. depth to hardpan 4 ft. Av. depth to hardpan 3 to 4 ft. Av. depth to hardpan 2Y 2 ft. ; drainage generally poor Av. depth to hardpan 2Y 2 ft. ; drainage usually poor Subject to overflow May include some hardpan areas Drainage poor ; hardpan ; not typical of series 6 in. to 6 ft. deep. Av. depth 3 ft. Alkali About 4H ft. to hardpan Nonagricultural Nonarable * Names given to some of the soil series in the older areas (Marysville, 1909) may not conform to later correlations and the rating values should not be confused with those for soils having similar names in other areas. 30. MARYSVILLE AREA The Marysville area is located on the east side of the Sacramento Valley and extends from the city of Sacramento to the northern boundary of Sutter County. This is a region of moderate winter rainfall and hot dry summers. The eastern edge of the area includes a fringe of hill lands which slope gradually to low rolling foothills and elevated terraces, and finally to the alluvial plain along the river at the western edge of the area. Sierra loam, a soil from basic igneous rocks, is the only group-VI soil 88 University of California — Experiment Station \ in the area and occupies the hill lands. Hardpan soils of group IV, which include the San Joaquin, Alamo, Marysville series, and Gridley silty clay loam, occupy the old alluvial terraces. The soils of group III are included in the lighter-textured Gridley soils, and Marcuse series. The Stockton soils (group V) occupy flat basin areas. The group-I soils include the Sacramento, Sutter, Feather, Bear, and Honcut series. The soils of the Sacramento, Stockton, and Alamo series are frequently poorly drained, and may contain alkali in injurious quantities. Table 37 shows the soil group, index rating, and grade of each soil type found in the Soil Survey of the Marysville Area. 36 This survey covers 598,400 acres, of which 217,600 acres are in grade 1 ; 87,168 acres in grade 2 ; and 74,880 acres in grade 3. The location of the different grades of soil for the Marysville area may be found in area 30 on map 1. 36 Strahorn, A. T., et al. Soil survey of the Marysville area, California. U. S. Dept. Agr. Bur. Soils, Field Oper. 1909:1689-740. (Out of print.) Bul. 599] A Rating of California Soils 89 TABLE 38 Merced Area: Eating of Soils in Accordance with the Storie Index Soil type* Aiken loam Aiken gravelly loam Mariposa sandy loam Mariposa silt loam Altamont sandy loam Altamont gravelly sandy loam Altamont loam Altamont gravelly loam Altamont stony loam Altamont clay adobe Redding stony loam Redding gravelly loam Redding gravelly clay loam San Joaquin sandy loam San Joaquin fine sandy loam... San Joaquin loam San Joaquin stony loam San Joaquin gravelly loam San Joaquin clay adobe San Joaquin gravelly clay loam Alamo clay adobe Alamo clay adobe, well- drained phase Montezuma clay adobe Fresno sand Fresno sand (S) Fresno sand (A) Fresno sandy loam Fresno sandy loam (S) Fresno sandy loam (A) Fresno finesandy loam Fresno fine sandy loam (S) Fresno finesandy loam (A) Fresno loam Fresno loam (S) Fresno loam (A) Fresno silty clay loam Fresno silty clay loam (S) Fresno silty clay loam (A) Fresno clay Fresno clay (S) Fresno clay (A) Oakdalesand Soil group Factors, per cent Index per cent Grade A B C VI 30 100 80 24 4 VI 20 70 80 11 5 VI 20 95 80 15 5 VI 20 100 80 16 5 VI 60 95 100 57 3 VI 30 65 80 16 5 VI 40 100 80 32 4 VI 30 70 '90 19 5 VI 20 70 90 13 5 VI 30 70 90 19 5 IV 20 70 100 14 5 IV 20 70 100 14 5 IV 20 55 100 11 5 IV 20 95 100 19 5 IV 25 100 100 25 4 IV 30 100 100 30 4 IV 20 70 100 14 5 IV 20 70 100 14 5 IV 25 60 100 15 5 IV 20 55 100 11 5 IV 30 70 60 13 5 IV 30 70 100 21 4 III 70 70 100 49 3 II 90 80 90 65 2 II 90 80 55 40 3 II 90 80 36 26 4 IV 50 95 100 48 3 IV 50 95 60 29 4 IV 50 95 40 19 5 IV 40 100 100 40 3 IV 40 100 60 24 4 IV 40 100 40 16 5 IV 30 100 100 30 4 IV 30 100 60 18 5 IV 30 100 40 12 5 IV 30 90 100 27 4 IV 30 90 60 16 5 IV 30 90 40 11 5 IV IV IV II 30 30 30 80 60 60 40 60 100 60 40 90 18 11 5 43 5 5 6 3 Remarks Av. depth l}4 ft.; erosive; low in humus Av. depth less than 1 ft. ; erosive; low in humus Av. depth 1 ft. ; low in humus Av. depth 1 ft.; erosive; low in humus Av. depth 4 ft. 1 to 2 ft. deep; erosive; not typ- ical of series 1 to 3 ft. deep; topography rough ; erosive Av. depth V/i ft. ; erosive Av. depth less than 1 ft. ; erosive Av. depth V/i ft. ; erosive Hardpan at 1 to 3 ft. Hardpan at 16 to 30 in. Hardpan at 1 to 3 ft. Hardpan at 18 to 30 in. Hardpan at 18 to 36 in. Hardpan at 30 to 48 in. Hardpan at 1 to 3 ft. Av. depth to hardpan 2 ft. Hardpan at 18 to 36 in. Hardpan at 1 to 3 ft. Hardpan at 3 ft. ; drainage poor Hardpan at 3 ft. Loamy sand; hummocky; hard- pan below 6 ft.; not typical of Slight alkali Alkali Hardpan at 3 to 6 ft. Slight alkali Alkali Hardpan at 2 to 6 ft. Slight alkali Alkali Hardpan at 1 to 3 ft. Slight alkali Alkali Hardpan at 2 to 4 ft. Slight alkali Alkali Av. depth to hardpan 3 ft. Slight alkali Alkali May have hardpan substratum ; low in humus * Names given to some of the soil series in the older areas (Merced, 1914) may not conform to later cor- relations and the rating values should not be confused with those for soils having similar names in other 90 University of California — Experiment Station TABLE 38 — Merced Area — (Concluded) Soil type 4 Oakdale sandy loam Hanford coarse sand Hanford coarse sand (S) Hanford coarse sand (A) Hanford sandy loam Hanford sandy loam (S) Hanford sandy loam (A) Hanford fine sandy loam Hanford fine sandy loam (S) Hanford fine sandy loam (A) Hanford silt loam Hanford silt loam (S) Hanford silt loam (A) Hanford clay loam Madera sand Madera sand (S) Madera sandy loam Madera sandy loam (S) Madera sandy loam (A) Madera fine sandy loam Madera finesandy loam (S)... Madera finesandy loam (A).. Madera loam Madera loam (S) Madera silt loam Madera silt loam (S) Madera silt loam (A) Madera clay Madera clay (S) Madera clay (A) Madera clay adobe Madera clay adobe (S) Madera clay adobe (A) Honcut fine sandy loam Merced silty clay loam Merced silty clay loam (S) Merced silty clay loam (A) Elder silt loam Elder silt loam (S) Elder silty clay loam Elder clay Dunesand Riverwash Rough stony land Tailings Factors, per cent Soil Index Grade group per Remarks A B C cent II 80 95 90 68 2 May have hardpan substratum ; low in humus 100 60 80 48 3 Low in humus 100 60 60 36 4 Slight alkali 100 60 40 24 4 Alkali 100 95 100 95 1 May include areas of Fresno soils 100 95 60 57 3 Slight alkali 100 95 40 38 4 Alkali 100 100 100 100 100 60 100 60 1 2 Slight alkali 100 100 40 40 3 Alkali 100 100 100 100 100 60 100 60 1 2 Slight alkali; drainage poor 100 100 40 40 3 Alkali; drainage poor 100 85 100 85 1 May vary considerably from typical IV 50 80 100 40 3 Hardpan at 4 to 6 ft. or deeper; loamy texture IV 50 80 60 24 4 Slight alkali IV 50 95 100 48 3 Hardpan at 4 to 6 ft. IV 50 95 60 29 4 Slight alkali IV 50 95 40 19 5 Alkali IV 40 100 100 40 3 Hardpan at 3 to 5 ft. IV 40 100 60 24 4 Slight alkali IV 40 100 40 16 5 Alkali IV 60 100 100 60 2 Av. depth to hardpan 6 ft. IV 60 100 60 36 4 Slight alkali IV 50 100 100 50 3 Hardpan at 3 to 5 ft. IV 50 100 60 30 4 Slight alkali IV 50 100 38 19 5 Alkali IV 50 60 100 30 4 Hardpan at 3 to 6 ft. IV 50 60 60 18 5 Slight alkali IV 50 60 40 12 5 Alkali IV 40 70 100 28 4 Hardpan at 3 to 5 ft. IV 40 70 60 17 5 Slight alkali IV 40 70 40 11 5 Alkali I 100 100 90 90 1 Subject to overflow III 70 90 80 50 3 Drainage poor III 70 90 60 38 4 Slight alkali III 70 90 40 25 4 Alkali I 100 100 100 100 1 Deep; friable I 100 100 60 60 2 Slight alkali I 100 90 100 90 1 May include areas of Honcut I 100 60 60 36 4 Alkali VII 9 6 Nonagricultural VII 1 6 Nonagricultural VII 1 6 Nonarable VII 1 6 Nonarable * Names given to some of the soil series in the older areas (Merced, 1914) may not conform to later cor- relations and the rating values should not be confused with those for soils having similar names in other areas. Bul. 599] A Rating of California Soils 91 31. MERCED AREA The Merced area includes practically all of that portion of Merced County which lies between the San Joaquin River on the west and the foothills of the Sierra Nevada on the east. With the exception of the foothill section, in which elevations reach 1,000 feet, the area has an average elevation of less than 200 feet. The rainfall in this region aver- ages about 12 to 14 inches annually ; the summers are long and dry, and the winters mild. The residual (group- VI) soils of the foothills are separated into the Aiken series, derived from basic igneous material ; the Mariposa series, derived from slate ; and the Altamont series, derived from mixed sand- stones and shales. The higher-terraced areas, bordering the foothills, include the hard- pan soils (group IV) of the Redding, San Joaquin, Alamo, and Madera series ; the Fresno series, most of which is also a group-IV soil, is found on the natter valley areas. The soils of group III are designated as the Montezuma and Merced series. The recent alluvial soils of the area were mapped as the Oakdale series (group II) and Hanford, Honcut, and Elder series (group I). Alkali is a serious problem on most of the natter lands and this fact has been taken into consideration in these ratings. A wide variety of fruit, truck, and general farm crops are grown on the better soils of the area, while grain and grain hay are produced on the poorer soils. Pasturage is the principal use for the alkali, shallow hardpan, and steeper areas. Table 38 shows the soil group, index rating, and grade for each soil type shown in the Soil Survey of the Merced Area. 37 The alkali designa- tions, S for slight alkali and A for moderate to strong alkali, are the same as those used in the soil-survey report. This survey covers 614,400 acres, but data on the areal distribution of alkali are not available, so that the area in each grade is not given. The location of the different grades of soil in the Merced area may be found in area 31 on map 2. 37 Watson, E. B., et al. Soil survey of the Merced area, California. U. S. Dept. Agr. Bur. Soils, Field Oper. 1914:2785-850. (Out of print.) 92 University of California — Experiment Station 32. MODESTO-TURLOCK AREA The major portion of the Modesto-Turlock area is located in Stanislaus County, although portions of both San Joaquin and Merced counties are included. The area lies at the lower end of the San Joaquin Valley, TABLE 39 Modesto-Turlock Area : Rating of Soils in Accordance with the Storie Index Soil type* Soil group Factors, per cent Index per cent Grade Remarks Fresno sandy loam. Fresno fine sandy loam. Fresno sand , Fresno fine sand Fresno loam. San Joaquin sandy loam. San Joaquin loam Arnold sandy loam Arnold fine sandy loam. Arnold loam Arnold clay adobe Sacramento silt loam Sacramento sandy loam Hanford silt loam Stockton loam Stockton clay loam Stockton clay adobe Oakdale coarse sandy loam.. Oakdale sandy loam Oakdale sand Modesto loam , Riverwash IV IV II II IV IV IV VI VI VI VI I I I I IV IV I I I III VII 60 50 30 60 100 100 100 100 40 40 100 100 100 70 95 100 65 100 95 100 95 100 100 60 100 95 100 100 95 70 90 100 65 100 100 100 100 100 100 100 100 100 100 100 90 90 100 100 100 100 100 100 100 100 100 100 90 100 65 70 Extent, depth, and hardness of hardpan variable; may con- tain alkali Depth of hardpan and alkali variable Usually without hardpan; not typical of series Usually without hardpan; may contain damaging quantities of alkali Av. depth to hardpan 3 ft. ; may contain alkali Av. depth to hardpan 2 l A ft. Av. depth to hardpan 2 ft. Not typical of Arnold in later Not typical Not typical Not typical Drainage often restricted; may contain alkali; not typical of Sacramento in later areas May contain alkali Some areas may contain alkali Not typical of the series Hardpan at 4 ft. Hardpan at 4 ft. May contain gravel May include some Fresno soil Fine sand and sand Nonagricultural * Names given to some of the soil series in the older areas (Modesto-Turlock, 1908) may not conform to later correlations and the rating values should not be confused with those for soils having similar names in other areas. where the rainfall is moderate and the climate is warm in summer and mild in winter. The Arnold series of soil occupies low rolling hills and is the only residual (group-VI) soil found in this area. The San Joaquin series in group IV occupies the higher portions of the area along its eastern Bul. 599] A Rating of California Soils 93 border, and the Fresno and Stockton series in the same group (except Stockton loam, group I) occupy low, poorly drained positions. The Modesto series is included in group III because of its dense substratum. The Fresno fine sand and sand are placed in group II since they do not contain a hardpan, as do the more typical members of the series. The remaining soils of the area consist of recent alluvial material (group I) and are included in the Sacramento, Hanford, and Oakdale series. Alkali is an important factor in certain locations, particularly in soils of the Fresno series. Fruit, alfalfa, truck, and grapes are extensively grown on the recent alluvial soils, and to a considerable extent on the other soils where alkali is not present in damaging quantities, and irrigation water is available. Table 39 shows the soil group, index rating, and grade for each soil type found in the Soil Survey of the Modest o-Turlock Area. 38 This sur- vey covers 517,120 acres, of which 70,336 acres are in grade 1 ; 34,688 acres in grade 2 ; and 152,896 acres in grade 3. The location of the different grades of soil in the Modesto-Turlock area may be found in area 32 on map 2. 38 Sweet, A. T., J. F. Warner, and L. C. Holmes. Soil survey of the Modesto-Tur- lock area, California. U. S. Dept. Agr. Bur. Soils, Field Oper. 1908:1229-94. (Out of print.) 94 University of California — Experiment Station TABLE 40 Napa Area : Rating of Soils in Accordance with the Storie Index Soil type* Konokti stony clay loam, brown phase Konokti stony clay loam, brown shallow phase Konokti stony clay loam, brown steep phase Konokti stony clay loam, rock-outcrop phase Aiken stony clay loam Butte stony loam Butte stony loam, steep phase Hugo clay loam Hugo clay loam, steep phase... Hugo clay loam, light-textured Phase Hugo fine sandy loam, reddish phase Los Osos clay loam Los Osos clay loam, steep phase Los Osos clay loam, light-tex- tured phase Denverton clay adobe Montezuma clay adobe Coombs gravelly loam Coombs gravelly loam, dark- colored phase Coombs stony loam Carnerosloam Carneros loam, dark-colored phase Carneros clay loam San Ysidro loam Hartley loam Hartley stony clay loam Keef ers gravelly clay loam Keefers gravelly clay loam, dark-colored phase Vina gravelly sandy loam Esparto clay loam Esparto gravelly loam Esparto clay loam, reddish phase Soil group VI VI VI VI III III III III III III III III III III III III III I II II Factors, per cent 40 100 95 95 95 100 85 85 95 70 70 70 100 70 100 100 85 100 100 60 70 85 65 85 70 85 90 80 50 85 100 50 100 40 80 50 100 50 100 100 100 100 100 100 70 100 100 100 100 100 100 Index per Grade Remarks Av. depth 3 ft. ; some areas not very stony ; erosive Shallow and very stony Av. depth 2 ft. ; steep slopes Av. depth 2 ft.; flatter slopes; less eroded than typical ; simi- lar to Butte 3 to 4 ft. deep; some areas not very stony and with gentle slopes Av. depth 2 ft.; steeper slopes subject to severe erosion Stony ; shallow and steep 3 to 3H ft. deep Shallow and steep ; erosive Stony loam; av. depth 12 in.; erosive 15 to 30 in. deep; badly eroded Av. depth 42 in. ; texture variable Shallow ; steep ; many land slips Av. depth 3 ft. Substratum variable in depth and density No gravel; somewhat shallower than typical Very shallow Fertility low Fertility low Drainage poor Drainage poor Erosion active Subdrainage poor Surface is loam ; subsoil gravelly Subsoil only is gravelly Very gravelly Texture variable Differs from typical in color only Series and type names as shown in preliminary correlation subject to change. Bul. 599] A Rating of California Soils TABLE 40 — Napa Area — (Continued) 95 Soil type* Esparto stony clay loam, red- dish phase Esparto silty clay loam Yolo sandy loam Yolo gravelly sandy loam Yolo loam Yolo clay loam Yolo gravelly clay loam Yolo clay loam, dark-colored phase Zamora silty clay loam Zamora gravelly silty clay loam Zamora silty clay Zamora silty clay, poorly drained phase Zamora silty clay, dark- colored phase Zamora clay adobe Sutter sandy loam Sutter sandy loam, light- textured phase Sutter loam Bale loam Bale loam, light-colored phase Bale gravelly loam Bale stony gravelly loam Bale clay loam Bale clay loam, heavy-tex- tured phase Bale loam, light-textured phase Bear Creek clay loam, light- textured phase Bear Creek gravelly clay loam, light-textured phase Bear Creek clay loam, shallow phase Bear Creek clay loam Ryde clay loam Alvisoclay Clear Lake clay adobe Calistoga gravelly loam Calistoga clay loam Calistoga gravelly clay loam.... Calistoga clay adobe Maxwell clay adobe Soil group II II II II II II II V II I I I I I I I III Factors, per cent 95 95 100 100 100 100 100 100 95 95 95 95 95 95 100 100 100 95 95 95 96 95 95 95 so 30 85 100 100 95 95 95 95 95 40 60 90 95 65 100 85 55 85 90 70 65 65 65 60 95 100 100 100 70 50 85 60 100 85 55 85 85 85 60 70 70 85 55 70 70 100 100 100 100 100 100 100 100 90 90 90 60 60 100 90 90 90 100 90 90 90 90 90 90 90 Index per cent 57 86 95 65 100 85 55 85 77 60 56 37 37 34 95 90 Grade Remarks Friable Includes some sandy areas Low water-holding capacity Deep; friable Deep; friable Low moisture holding capacity Deep ; friable Drainage somewhat restricted Winter drainage sometimes poor Poorly drained in winter Poorly drained Drainage deficient Loamy sand to fine sand; low moisture-holding capacity Subdrainage restricted Drainage somewhat restricted ; may be alkaline Gravelly; not typical of series; drainage poor locally Drainage somewhat restricted Drainage somewhat restricted Drainage somewhat restricted Drainage poor; clay Fine sandy loam; subdrainage somewhat restricted Subsoil tight ; drainage restricted Gravelly Shallow overwash; drainage poor Drainage poor in winter Highly organic ; drainage poor Strong alkali; drainage poor Drainage poor Drainage poor Puddles; winter drainage badly restricted Drainage badly restricted Drainage poor Drainage poor Series and type names as shown in preliminary correlation subject to change. 96 University of California — Experiment Station TABLE 40— Napa Area— (Concluded) Soil type* Maxwell clay adobe, brown phase Maxwell clay adobe, gray phase Capay clay Dublin clay adobe Dublin clay adobe, overwash phase Rough stony land Rough mountain land Riverwash Soil group Factors, pei cent Index per cent Grade A B C III 40 70 70 20 4 III 60 80 70 34 4 III 60 60 90 32 4 I 100 70 60 42 3 I 100 100 50 50 3 VII 3 6 VII 5 6 VII 1 6 Remarks Drainage poor Lighter and more friable than typical Drainage poor in winter Drainage poor Overwash of Yolo fine sandy loam, subdrainage poor Nonarable Nonarable Nonagricultural Series and type names as shown in preliminary correlation subject to change. 33. NAPA AREA The Napa area lies in central California and includes practically all of Napa County. The area is made up of a number of small parallel valleys, of which Napa is the largest, and the intervening ridges and mountain- ous areas. This area receives an annual rainfall ranging from 20 to 40 inches, which occurs almost entirely during the winter months. Both summer and winter climates are mild. A wide range in elevation, from sea level to nearly 3,000 feet, and a wide variety of geological formations have resulted in many soil differences. In group VI are found the Konokti and Aiken series, derived from basaltic rocks ; the Butte, from rhyolite ; and the Hugo and Los Osos, from sandstones and shales. The Denverton, Montezuma, Coombs, Car- neros, San Ysidro, Hartley, Keefers, Maxwell, and Capay series are group-Ill soils. The group-II soils consist of the Bale, Bear Creek, and Esparto series, and the group-I soils of the Vina, Yolo, Zamora, Sutter, Ryde, Alviso, Clear Lake, Calistoga, and Dublin series. The majority of the soils are heavy-textured and have somewhat restricted drainage, especially during the winter season. At the lower end of the Napa Valley, where the Napa River delta is in contact with the brackish waters of San Pablo Bay, many of the soils are poorly drained and contain alkali. A wide range of crops are grown in this area. Grapes and deciduous fruits occupy much of the valley floor, with grain, truck crops, and miscellaneous annuals throughout the area. Because of the heavy tex- ture of many of the soils, prunes and pears are the predominating de- ciduous fruits. Bul. 599] A Rating of California Soils 97 Table 40 gives the soil group, index rating, and grade for the several soil types found in the Soil Survey of the Napa Area. 39 This survey cov- ers 393,600 acres, but data are not available showing the areal distribu- tion of the several soil types. The location of the various grades of soil in the Napa area may be found in area 33 on map 3. 39 Cosby, S. W., and E. J. Carpenter. Soil survey of the Napa area, California. U. S. Dept. Agr. Bur. Chem. and Soils. (In press.) 98 University of California — Experiment Station TABLE 41 Oceanside Area : Eating of Soils in Accordance with the Storie Index Soil type Soil group Factors, per cent Index per cent Grade Remarks Fallbrook fine sandy loam... Vista sandy loam Escondido silt loam Konokti stony loam Las Posas stony fine sandy loam Carlsbad loamy fine sand.... Carlsbad loamy fine sand, gravelly phase Altamont clay loam Altamont clay loam, gravelly phase Altamont clay Diablo clay adobe Ayar clay loam Linneclay Hanford finesandy loam Tujunga fine sand Laguna loamy sand Foster finesandy loam Alvisoloam Elkhorn loamy sand Greenfield sandy loam Greenfield sandy loam, cal- careous-subsoil phase Ramona sandy loam Ramona sandy loam, stony phase Botella loamy sand Botella loamy sand, brown phase Botella sandy clay loam Botella sandy clay loam, brown phase San Marcos finesandy loam San Marcos loamy fine sand Salinas clay loam Redding gravelly sandy loam.. Olivenhain loamy fine sand Las Flores loamy fine sand Las Flores loamy fine sand, eroded phase Tierraloam Huerhuero finesandy loam Merriam sandy loam Merriam finesandy loam Merriam finesandy loam, clay VI VI VI VI VI VI VI VI VI VI VI VI VI I I I I I II I I II II I I I I II II II IV V V V III III III III GO 40 40 40 40 40 40 50 50 40 40 100 95 95 100 100 85 100 100 100 95 100 70 85 85 85 55 50 50 85 50 100 65 90 100 100 80 95 95 95 65 80 80 85 85 100 90 85 65 80 90 80 100 100 95 100 50 100 100 100 100 100 60 100 100 100 100 100 50 90 90 5 90 100 100 100 100 100 100 90 40 40 100 100 'JO 100 100 100 27 27 18 25 25 34 20 100 31 77 90 5 01 95 95 25 30 to 60 in. deep; some stony 30 to 60 in. deep; erosive 24 to 40 in. deep Less than 3 ft. deep; high stone content Usually less than 3 ft. deep ; stone content and texture variable 20 to 40 in. deep; eroded 20 to 40 in. deep ; eroded Erosion active Eroded and broken topography 30 to 40 in. deep 18 to 48 in. deep 18 to 40 in. deep Subject to overflow Eroded May contain alkali High in salts ; tidal land Low in humus Somewhat variable Differs from typical in color only Fair drainage Not typical of series Some alkali ; drainage fair to poor Some alkali ; drainage fair to poor Hardpan at shallow depth; very acid Shallow soil Shallow soil ; eroded Shallow soil; heavy clay sub- soils; very badly eroded Shallow ; drainage poor Subsoil at times approaches hardpan Bul. 599] a Rating of California Soils TABLE 41 — Oceanside Area — {Concluded) Soil type 99 Monserate sandy loam Rough broken land Rough stony land Tidal marsh Coastal beach, dunesand.. Riverwash Soil group Factors, per cent Index per cent. Grade A B C V 40 95 100 38 4 VII 5 6 VII 2 6 VII 2 6 VII 1 6 VII 1 6 Remarks Hardpan soil Nonarable Nonarable Nonagricultural Nonagricultural Nonagricultural 34. OCEANSIDE AREA The Oceanside area is located in west central San Diego County, and extends from the ocean on the west back a distance of about 20 miles into the hills on the east. This is a region of mild summer and winter climate. An average rainfall of about 13 inches occurs during the winter months. Fog is common along the coast during the summer. The land surface is made up of low gently rolling terraces near the coast, which increase somewhat in elevation toward the east and merge into the rougher, steeper hills of the back country. Dissecting the area are a number of small valleys through which now the streams draining the uplands. The group-VI soils of the area consist of the Fallbrook and Vista series, from granitic sources ; the Konokti and Las Posas series, from basic igneous rocks ; the Altamont, Diablo, Ayar, and Linne series, from shale and limestone ; the Carlsbad series, from sandstone ; and the Escon- dido series, from basic schists. Throughout the central portion of the area are found the soils of the Olivenhain, Las Flores, Tierra, and Monserate series resting on consolidated substratum of clay (group V) ; and the Kedding series, which has a dense hardpan (group IV) . The Huerhuero and Merriam series are group-Ill soils, and the Elkhorn, Ramona, San Marcos, and Salinas series are group-II soils. The soils of the Tujunga, Laguna, Foster, Alviso, Greenfield, and Botella series occupy the stream-laid valleys and show little or no profile development (group I). The Alviso series is uniformly strongly alkaline and in poorly drained areas some of the other recent soils may contain alkali. The crops of this area are varied. Irrigation is used for practically all cultivated crops except grain and beans. Citrus fruits, grapes, and some deciduous fruits are grown on the Fallbrook and Vista series of soils. Avocados, oranges, and other subtropical fruits, flowers, bulbs, and truck crops are grown along the coast on the Carlsbad, Elkhorn, and other soils. Beans, grain, and other field crops are grown throughout 100 University of California — Experiment Station the area. The equitable climate of this area has probably had a greater influence on the type of agriculture developed than has the character of the soil. Table 41 shows the soil group, index rating, and grade for the various soils found in the Soil Survey of the Oceanside Area. 40 This survey covers an area of 369,280 acres, of which about one-third is nonagricul- tural because of topography or excessive alkali. The grade-1 soils are limited to 26,624 acres, while the grade-2 soils include 62,144 acres, and the grade-3 soils 65,920 acres. The location of the several grades of soil in the Oceanside area, may be found in area 34 on map 4. 40 Storie, R. Earl, and E. J. Carpenter. Soil survey of the Oceanside area, Cali- fornia. U. S. Dept. Agr. Bur. Chem. and Soils, Ser. 1929, Rept. 11:1-41. Bul. 599] A Rating of California Soils 101 TABLE 42 Oroville Area: Eating of Soils in Accordance with the Storie Index Soil type Columbia very fine sandy loam Columbia loam Columbia loam, shallow phase Columbia silty clay loam Gridley clay loam Gridley clay loam, overwash phase Gridley clay Gridley clay, dark phase Wymanloam Wyman loam, silty phase Wyman loam, poorly drained phase Wyman gravelly loam Landlowloam Landlowclay Landlow clay adobe Kimball loam Kimball loam, gravelly phase.. Redding gravelly sandy loam.. Redding gravelly sandy loam, shallow phase Aiken clay loam Aiken clay loam, stony phase Aiken clay loam, rock-outcrop phase Stockton clay adobe Stockton clay adobe, brown phase Stockton clay adobe, over- wash phase Stockton clay adobe, gray phase Marvin silty clay loam Marvin silty clay loam, poorly drained phase Marvin silty clay loam, light- textured phase Sierra sandy loam Rocklyn fine sandy loam Rockly n fine sandy loam , gravelly phase Rocklyn fine sandy loam, heavy phase Corning gravelly sandy loam Honcutloam Soil group I I I I III III III III II II II II V V V. Ill III IV IV VI VI VI V V II II II VI IV IV IV III I Factors, per cent 100 100 100 100 40 40 40 90 90 90 50 20 20 20 40 100 100 100 100 90 85 100 100 100 100 70 100 50 60 100 70 65 65 85 60 85 70 70 100 100 100 70 85 65 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 80 100 100 100 40 100 50 90 100 100 100 100 100 100 Index per cent 100 100 90 28 36 17 26 100 Grade Remarks Deep; friable Deep; friable 3 to 4 ft. of overwash on consoli- dated substratum Columbia very fine sandy loam over Gridley Shallow; drainage poor Silt loam subsoil Drainage poor Shallow; 36 in. to substratum Shallow; 36 in. deep Shallow; 36 in. deep 4 to 5 ft. deep; substratum very dense Hardpanat26to36in. Very shallow; hardpan at 14 to 32 in. 24 in. deep Consolidated substratum at 30 in. Consolidated substratum at 30 in. Shallow Ramada over Stockton Drainage very poor Drainage poor Drainage slightly restricted Av. depth 30 in. 18 to 28 in. to hardpan Shallow and gravelly Shallow clay loam Very gravelly; compact 102 University of California — Experiment Station TABLE 42 — Oroville Area — (Concluded) Soil type Soil group Factors, per cent Index per cent Grade Remarks Honcut loam, heavy phase Honcutloam, compact-subsoil phase Honcut sandy loam Sacramento clay Nordloam Sutter sandy loam Sutter sandy loam, heavy phase Ramada silt loam Anita clay adobe Tuscan gravelly clay loam Tuscan gravelly clay loam, stony phase Mariposa loam Mariposa loam, rock-outcrop phase Placer diggings Tailings Rough broken and stony land Scabland I I II I I I I II V V VI VI VII VII VII VII 100 85 100 95 90 95 95 85 15 20 85 100 100 50 100 100 85 100 60 55 55 100 100 100 100 100 100 95 100 100 100 70 85 100 38 Clay loam Subsoil drainage restricted Drainage poor; may have con- solidated substratum Topograhy uneven Loam to clay loam Outwash from hydraulic min- ing; stratified Drainage restricted Nonarable Nonarable Shallow Nonarable Nonarable Nonarable Nonarable Nonarable 35. OROVILLE AREA The Oroville area lies in the northern part of the Sacramento Valley and covers the southwestern portion of Butte County extending from the Sacramento River eastward into the foothills of the Sierra Nevada. This region has a mean annual rainfall of from 25 to 30 inches, most of which occurs during the winter months. The winters are cool and the summers are hot and dry. The foothill sections of this area are made up of group-VI soils which include the Aiken series, from basic igneous rocks ; Sierra series, from granitic material ; and the Mariposa series, from schists. Lying adjacent to the residual soils, but at a lower elevation, are the group-V soils of the Tuscan series, and the group IV soils of the Redding and Rocklyn series. At a yet lower elevation and extending well out into the valley are the group-Ill soils, which include the Corning, Kimball, and Grid- ley series. The group-II soils of the Wyman, Marvin, Sacramento, and Anita series occupy the lower, natter valley lands adjacent to the more strictly basin soils of the Landlow and Stockton series. These latter two series are developed on consolidated substratum and are considered as group-V soils. The remaining soils of this survey, represented by the Columbia, Honcut, Nord, and Sutter series, are recent alluvial material Bul. 599] a Rating of California Soils 103 (group I) which show practically no profile development. Drainage is poor on most of the low-lying areas, which include the Stockton, Land- low, Sacramento, and portions of the Anita, Gridley, Marvin, and Wy- man series. The crops of this area range from deciduous fruits on the Columbia, Gridley, and Wyman series; citrus fruits on the Aiken, Sierra, and Redding series; rice and grain on the Stockton, Sacramento, and re- lated series ; to miscellaneous crops and general farming throughout the area. Table 42 shows the soil group, index rating, and grade for the various soils found in the Soil Survey of the Oroville Area. 41 This survey covers 326,400 acres, of which 76,608 acres are in grade 1 ; 23,680 acres in grade 2 ; and 10,816 acres in grade 3. The location of the various grades of soil in the Oroville area may be found in area 35 on map 1. ±i Carpenter, E. J., et al. Soil survey of the Oroville area, California. TJ. S. Dept. Agr. Bur. Chem. and Soils, Ser. 1926, Kept. 4:1-63. 104 University of California — Experiment Station 36. PAJARO VALLEY AREA The Pajaro Valley area is located in Santa Cruz and Monterey counties, and includes the lower portion of the Pajaro River and Corralitos Creek valleys and adjacent hills. The rainfall in this area averages about 25 inches a year, and the temperatures are mild both in summer and winter. TABLE 43 Pajaro Valley Area : Eating of Soils in Accordance with the Storie Index Soil type* Pajaro sand Pajaro sandy loam Pajaro finesandy loam Pajaro light silt loam Pajaro loam Pajaro silt loam Pajaro silty clay Pajaro clay loam adobe Santa Cruz sand Santa Cruz sandy loam Santa Cruz loam Watsonville sandy loam Watsonville loam Watsonville clay loam adobe. Salsipuedes loam Corralitos loam Monterey sandy loam Encina sandy loam Peat Alvisoclay Dunesand Soil group Factors, pei cent Index per cent Grade A B C I 100 60 50 30 4 I 100 95 100 95 1 I 100 100 100 100 1 I 100 100 90 90 1 I 100 100 100 100 1 I 100 100 100 100 1 I 100 65 100 65 2 I 100 85 80 68 2 VI 80 60 80 38 4 VI 80 95 80 61 2 VI 80 100 80 64 2 III 70 95 80 53 3 III 60 100 80 48 3 III 60 85 80 41 3 II 80 100 100 80 1 I 100 100 100 100 1 VI 40 95 80 30 4 VI 60 95 100 57 3 I 70 2 I 100 60 10 6 2 6 6 Remarks Coarse; incoherent ; overflowed Friable; deep Friable; deep Subject to occasional overflow Friable; texture somewhat var- iable Drainage restricted Over 6 ft. deep ; erosive ; Moro Cojo in later surveys Over 6 ft. deep; erosive; Moro Cojo in later surveys Over 6 ft. deep; subject to ero- sion ; Moro Cojo in later surveys Av. depth 5 ft. ; erosive Av. depth 3 ft. ; erosive Av. depth Z l A ft. ; erosive Deep; friable 4 ft. to hardpan; drainage var- iable 4 ft. deep Heavy ; highly alkaline Rough topography; nonagricul- tural * Names given to some of the soil series in the older areas (Pajaro Valley, 1908) may not conform to later correlations and the rating values given should not be confused with those having similar names in other areas. The hilly sections of this area are composed of the Santa Cruz, Monte- rey, and Encina series of group VI and the Watsonville series of group III. The remaining soils are all recent deposits (group I) and are in- cluded in the Pajaro, Salsipuedes, and Alviso series, the latter being highly alkaline. Apples and berries are grown extensively on the residual, as well as the alluvial soils of the area. Truck crops, seeds, and other annuals are grown on the alluval soils. Bul. 599] A Rating of California Soils 105 Table 43 gives the soil group, index rating, and grade for the various soils found in the Soil Survey of the Pajaro Valley.* 2 This survey covers 68,620 acres, of which 18,304 acres are in grade 1 ; 7,040 acres in grade 2 ; and 26,188 acres in grade 3. The location of the soil grades in the Pajaro Valley area may be found in area 36 on map 3. 42 Mackie, W. W. Soil survey of the Pajaro Valley, California. U. S. Dept. Agr. Bur. Soils, Field Oper. 1908:1331-72. (Out of print.) 106 University of California — Experiment Station 37. PALO VERDE AREA The Palo Verde area is located in the extreme northeastern part of River- side County on the west bank of the Colorado River. This is a part of the Colorado River desert ; the rainfall is extremely low, the summers long and hot, and the winters mild. TABLE 44 Palo Verde Area : Eating of Soils in Accordance with the Storie Index Soil type Gila very fine sand Gila silt loam Rositas fine sand Rositas fine sandy loam Rositas very fine sandy loam.... Holt ville silt loam Holtvillesilty clay loam Holtville silty clay Holtville clay Meloland very fine sandy loam Meloland very fine sandy loam, stratified-subsoil phase Imperial very fine sandy loam Imperial very fine sandy loam, stratified-subsoil phase Imperial silty clay loam Imperial silty clay loam, stratified-subsoil phase Imperial clay Imperial clay, stratified-sub- soil phase Carrizosand Superstition gravelly sand Superstition gravelly sand, stony phase Superstition sand Tijeras stony sandy loam Tijeras sandy loam Tijeras gravelly loam Alluvial soils, undifferentiated Riverwash Rough stony land Rough broken land Soil group I I I I I I I I I I I I I I I I I I I I I V V V I VII VII VII Factors, per cent 100 100 100 100 100 95 95 95 95 85* 90* 85* 85* 75* 85* 75* 85* 100 95 95 95 40 40 40 100 65 100 100 100 90 60 50 100 100 100 100 90 55 55 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 40 80 100 40 40 40 Index per cent 100 65 100 100 95 86 57 48 85 85 85 Grade Remarks Very recent deposits ; lack uni- formity Very recent deposits ; lack uni- formity Wind-blown ; may be hummocky Texture and depth variable Slightly hummocky Light- textured subsoil Depth variable Very similar to Meloland Subsoil variable Subsoil variable Subsoil variable Subject to overflow Coarse; leachy Very coarse and leachy Leachy Rough and stony All subject to overflow Subject to overflow Very rough Very rough * Factor A for Meloland and Imperial series reduced below normal for group I on account of very heavy subsoils. Index computed on alkali-free basis. See table 45 for values where alkali is present. The area consists of two parts, a river floodplain upon which all of the present agricultural development is located, and a mesa. The valley or flood-plain soils are all recent alluvial deposits (group I) from the Colorado River, and are designated as the Gila, Rositas, Holtville, Melo- Bul. 599] A Rating of California Soils 107 land, and Imperial series. The mesa soils are mapped as Carrizo (group I), Superstition (groups I and II), and Tijeras (group V) series. Irrigation is required for all crops, the supply being diverted from the Colorado River. Alkali is an important consideration and materially affects the agricultural value of the soils in this area. TABLE 45 Effect of Varying Amounts of Alkali on the Index Value of Soils in the Palo Verde Area Soil type F, alkali- free, per cent M, slightly- affected, per cent A, moderately affected, per cent S, strongly affected, per cent Gila very fine sand Gila silt loam Rositas fine sand Rositas fine sandy loam Rositas very fine sandy loam Holtville silt loam Holtville silty clay loam Holtville silty clay Holtville clay Meloland very fine sandy loam Meloland very fine sandy loam stratified-subsoil phase Imperial very fine sandy loam Imperial very fine sandy loam, stratified-subsoil phase Imperial silty clay loam Imperial silty clay loam, stratified-subsoil phase... Imperial clay Imperial clay, stratified-subsoil phase Carrizo sand Superstition gravelly sand Superstition gravelly sand, stony phase Superstition sand Tijeras stony sandy loam Tijeras sandy loam Tijeras gravelly loam Alluvial soils, undifferentiated Riverwash Rough stony land Rough broken land 100 65 100 100 95 86 57 48 85 90 85 85 68 77 41 47 24 22 11 57 10 15 11 15 2 1 1 Alfalfa is the principal crop, although grain, corn, cotton, and simi- lar annual crops are also extensively produced. Table 44 shows the soil group, index rating, and grade for each soil type found in the Soil Survey of the Palo Verde Area** for alkali-free conditions only. Table 45 gives the index rating for the various soil types when affected by alkali to the degree of intensity indicated. The symbol M indicates slightly affected; A, moderately affected; and S, strongly affected with alkali. This survey covers 270,720 acres, but data are not available on the areal extent of the different degrees of alkali. The soil grades in the Palo Verde area may be found in area 37, map 4. 43 Kocher, A. E., and F. O. Youngs. Soil survey of the Palo Verde area, Cali- fornia. U. S. Dept. Agr. Bur. Soils, Field Oper. 1922:571-625. 1926. 108 University op California — Experiment Station 38. PASADENA AREA The Pasadena area is located in eastern Los Angeles County and em- braces the upper portion of the San Gabriel and adjacent valleys. It lies between the San Gabriel Mountains on the north and the Puente TABLE 46 Pasadena Area : Eating of Soils in Accordance with the Storie Index Soil type Soil group Altamont loam Altamont clay loam Altamont clay Altamont clay, dark-colored phase Holland sandy loam Holland loam Ramona stony loam Ramona gravelly loam Ramona loam Ramona clay loam Placentia loam Antioch silty clay loam Hanford stony sandy loam Hanford gravelly sandy loam. Hanford sand Hanford fine sand Hanford fine sand, stone sym- bols* Hanford sandy loam Hanford fine sandy loam Hanford loam Tujunga stony sand Tujunga stony sand, overflow phase Chinoloam Chino silty clay loam Chino silty clay loam, adobe phase Yolo loam Yolo clay loam Yolo clay loam, heavy phase.. Rough broken land Rough stony land Riverwash VI VI VI VI VI VI II II II II III III I I I I I I I I I I I I I I I I VII VII VII Factors, per cent 55 40 50 70 60 60 85 85 85 85 60 50 100 100 100 100 100 100 100 100 100 100 95 95 95 100 100 100 100 85 60 95 100 70 70 100 85 100 90 65 65 60 65 45 95 100 100 20 100 70 100 85 70 80 100 100 100 80 80 60 90 100 100 80 100 80 100 100 100 100 100 100 100 90 70 100 100 100 Index per cent 44 34 30 42 46 48 36 54 85 72 48 45 52 65 60 65 45 95 100 100 18 12 76 51 47 100 85 70 Grade Remarks 2 to 5 ft. deep; hilly ; erosive 2 ft. deep; hilly 2H ft. deep 4 to 6 ft. deep 3 to 5 ft. deep; hilly ; erosive 3 to 5 ft. deep; eroded Steep topography ; very stony Texture variable; erosive Local areas poorly drained Steep; eroded Local areas poorly drained Gravel and stones in subsoil Leachy Deep; friable Stony areas Deep; fertile Leachy ; low in humus Leachy ; low in humus Drainage fair Drainage fair to poor; may con- tain alkali Clay adobe ; drainage fair Deep; friable Black clay adobe Nonarable Nonarable Nonagricultural * Areas where the soil survey indicates, by symbols, the presence of stone. Hills on the south. The temperatures are mild, both winter and summer, and the rainfall moderate. The soils of this area include the Altamont series from sedimentary rocks and the Holland from granitic material in group VI ; the Placentia Bul. 599] A Rating of California Soils 10^ and Antioch series in group III ; the Ramona series in group II ; and the Hanford, Chino, Tujunga, and Yolo series in group I. Drainage is not a serious problem in this area, although locally there may be some poorly drained and alkali lands. This area is thickly popu- lated, the western portion being decidedly urban, and the crops grown are those of a thickly settled community. Oranges, avocados, and lemons are extensively produced on the Ramona and Placentia soils, with truck, citrus, and walnuts being produced on the Hanford, Yolo, and Chino soils. Most crops are irrigated, the water being obtained largely from underground sources by pumping. In the western part of the area, urban development and related factors have had a greater influence on land use than has the inherent quality of the soil. Table 46 gives the soil group, index value, and grade for the several soil types found in the Soil Survey of the Pasadena Area. 44 This survey covers 270,720 acres, of which 86,848 acres are in grade 1 ; 42,944 acres in grade 2 ; and 46,528 acres in grade 3. About one-fourth of the area is mountainous or riverwash, and therefore is nonarable. The location of the various grades of soil for the Pasadena area may be found in area 38 on map 4. 44 Eckman, E. C, and C. J. Zinn. Soil survey of the Pasadena area, California. U. S. Dept. Agr. Bur. Soils, Field Oper. 1915:1-56. 1917. 110 University of California — Experiment Station TABLE 47 Paso Eobles Area : Eating of Soils in Accordance with the Storie Index Soil type Sheddloam Shedd loam, gravelly phase Ayar clay loam Ayar clay loam, gravelly phase Nacimiento clay loam Nacimiento clay loam, grav- elly phase Zaca clay loam Zaca gravelly clay loam.... Linne clay loam Linne gravelly clay loam.. Atascadero sandy loam.... Atascadero sandy loam, heavy-textured phase... Atascadero sandy loam, gray phase Hugo sandy loam Hugo sandy loam, dark- colored phase Hugo clay loam Salinas loamy sand Salinas loamy sand, brown phase Salinas fine sand Salinas fine sandy loam Salinas fine sandy loam, grav- elly phase Salinas very fine sandy loam.. Salinas loam Salinas loam, heavy-textured phase Salinas clay loam Salinas clay Hames sandy loam Hames sandy loam, heavy- textured phase Hames sandy loam, friable- subsoil phase Hames gravelly sandy loam... Hames gravelly sandy loam, red phase Hames gravelly sandy loam, dark phase Huerhuero sandy loam Huerhuero sandy loam, gravelly phase Soil group VI VI VI VI VI VI VI VI VI VI V VI VI VI II II II II II II II II II II III III II III III III III III Factors, per cent 50 50 100 100 70 85 55 85 55 85 55 85 55 95 85 65 100 70 100 100 85 85 6.0 95 100 70 65 65 65 95 65 100 100 90 80 80 80 90 100 90 100 100 80 100 100 100 100 100 100 25 100 100 100 80 80 80 85 90 Index per cent Grade Remarks 4 ft. deep; eroded 1 x /i ft. deep ; steep ; eroded V/2 ft. deep; texture variable 2J^ ft. deep; gravelly 3 ft. deep Shallow; steep; erosive 3 l A ft. deep; dissected by drain- ageways Erosive 33^ ft. deep; somewhat erosive Gravelly throughout Shallow; subsoil drainage poor Clay loam texture; subsoil drainage poor Shallow; mapped as Arnold in other areas 3H ft. deep 5 to 6 ft. deep Deep; friable Variable Similar to loamy sand Subject to overflow Friable; gravelly May contain considerable amounts of alkali Good moisture; friable Clay loam Gravelly in places Alkali ; badly eroded Loam texture Gravelly loam; not typical of series Eroded Eroded Drainage poor in subsoil Hog- wallow topography Dense gravelly subsoil Bul. 599] a Eating of California Soils TABLE 47 — Paso Eobles Area — (Concluded) 111 Soil type Soil group Factors, per cent Index per cent Grade Remarks Huerhuero sandy loam, friable-subsoil phase... Montezuma clay loam Montezuma clay loam, grav elly phase Montezuma clay loam, heavy phase Lockwood gravelly sandy loam Lockwood gravelly sandy loam, hardpan phase Yolo fine sandy loam. Yolo loam Metz fine sandy loam Metz fine sand Dublin clay Hanf ord sandy loam Foster loamy sand Agueda fine sandy loam Agueda clay loam Elder gravelly sandy loam.. Botella clay loam Commatti clay loam Commatti clay loam, gravelly phase Commatti sandy loam Chualar sandy loam Docas clay loam Docas clay loam, brown phase Santa Lucia gravelly loam Santa Lucia gravelly loam, shallow phase Holland sandy loam Rough mountainous land Riverwash Rough broken and stony land II III III III III IV I I I I I I I I I I I II II II II II II VI VI VI VII VII VII 80 70 40 100 100 100 100 100 100 100 100 100 100 90 85 100 85 55 65 65 100 100 100 65 60 95 80 100 85 65 85 85 70 95 95 85 85 70 70 95 100 100 100 100 100 80 40 80 100 70 80 100 100 100 100 100 100 90 100 100 90 72 44 26 Not typical of series; contains gravelly areas Clay Hardpan at Z X A ft.; not typical of series Some areas subject to overflow; texture variable Some areas subject to overflow Friable; texture variable Flood plain; overflow Drainage poor locally Includes gravelly areas Drainage poor locally Drainage poor locally Includes clay Includes loamy areas Includes gravelly areas Includes gravelly areas Eroded terraces Slightly eroded Slightly eroded 3 ft. deep; often very steep Very shallow 2J^ ft. deep; low in humus Nonarable Nonagricultural Nonarable 39. PASO EOBLES AREA The Paso Robles area is located midway between Los Angeles and San Francisco, and includes about two-thirds of the northern half of San Luis Obispo County and a few square miles of Kern County. In general, the area is hilly to mountainous with flat alluvial terraces occupying a portion of the central part between the Salinas River and Estrella Creek, and narrow valleys along the Salinas River, Huerhuero Creek, Estrella Creek, and their tributaries. The climate consists of hot, dry summers and cool winters, with a rainfall that ranges from about 28 inches at Santa Margarita to less than 10 inches at Shandon. 112 University of California — Experiment Station The group- VI soils which occupy the hilly lands of this area are the Shedd, Ayar, Nacimiento, Zaca, Linne, Hugo, Santa Lucia, and Holland series. The Atascadero series is a group-V soil. The hardpan phase of the Lockwood gravelly sandy loam is the only soil type in this area having true hardpan, group IV. In group III are found the Hames, Huerhuero, Montezuma, and Lockwood series. In group II are found the Salinas, Commatti, Chualar, and Docas series, and certain friable-subsoil phases of the Hames and Huerhuero series. The soils of the Yolo, Metz, Dublin, Hanford, Foster, Agueda, Elder, and Botella series are in group I. The residual soils are used largely for grain, although some almonds are grown on them. The recent alluvial soils are devoted to a wide range of truck and field crops. Irrigation is practiced to some extent on the better soils. Table 47 shows the soil group, index rating, and grade for each soil type in the Soil Survey of the Paso Robles Area. 45 There are 821,120 acres included in this survey, nearly one-third of which are nonarable on account of steep and rough broken topography. There are 49,280 acres in grade 1 ; 35,648 acres in grade 2 ; and 355,072 acres in grade 3. The location of the various grades of soil in the Paso Robles area may be found in area 39 on map 3. 45 Carpenter, E. J., and E. Earl Storie. Soil survey of the Paso Robles area, California. U. S. Dept. Agr. Bur. Chem. and Soils, Ser. 1928, Kept. 34:1-67. Bul. 599] A Rating of California Soils 113 40. PLACERVILLE AREA The Placerville area comprises the western third of Eldorado County and is entirely within the zone termed the "Sierra Nevada Foothills." The area is gently sloping to hilly on the west, and mountainous on the TABLE 48 Placerville Area : Eating of Soils in Accordance with the Storie Index Soil type Aiken clay loam Aiken clay loam, deep phase.... Aiken clay loam, shallow phase Aiken clay Aiken stony clay loam Holland loamy sand Holland loamy sand, rock- outcrop symbols* Holland fine sandy loam Holland fine sandy loam, rock outcrop symbols* Sierra loam Sierra loam, rock outcrop symbols* Sierra clay loam Sierra stony clay loam Diamond Springs loam Diamond Springs loam, stony phase Sites clay loam Sites clay loam, shallow phase Sites stony loam Mariposa silt loam Mariposa silt loam, shallow phase Mariposa silt loam, brown phase Olympic loam Honcutloam Rough mountainous land Placer diggings and tailings Rough stony land Soil group Factors, per cent Index per cent Grade A B c VI 70 85 90 54 3 VI 80 85 90 61 2 VI 30 85 100 26 4 VI 70 60 100 42 3 VI 50 60 80 24 4 VI 60 80 100 48 3 VI 60 80 80 38 4 VI 60 100 100 60 2 VI 60 80 100 48 3 VI 60 100 100 60 2 VI 60 80 100 48 3 VI 50 85 100 43 3 VI 40 50 90 18 5 VI 50 100 80 40 3 VI 50 60 80 24 4 VI 50 85 100 43 3 VI 25 85 90 19 5 VI 30 70 90 19 5 VI 25 100 90 23 4 VI 20 100 50 10 5 VI 20 70 100 14 5 VI 50 100 100 50 3 I 90 100 80 72 2 VII 9 6 VII 3 6 VII 3 6 Remarks 4 ft. deep; erosive Deep ; somewhat eroded \ x /z ft. deep; stony in places 2H ft. deep Moderately acid; 4 ft. deep Rock outcrop 3 ft. or more deep Amount of rock variable Z X A ft. deep Amount of rock variable 2]/ 2 ft. deep Shallow; stony Av. 33 in. deep; infertile V/i ft. deep; stony 2 X A ft. deep \ l A ft. deep; eroded 21 in. deep; eroded 1H ft. deep; eroded Badly eroded Stony loam ; shallow 2]/ 2 ft. deep Includes all alluvial soils Nonarable Largely nonarable Nonagricultural * Areas where the soil survey indicates, by symbols, the presence of rock outcrop, but which are not described as a separate type in the report. eastern border, with elevations ranging from about 400 feet to 3,500 feet. The deep canyons of the American and Cosumnes rivers cut through the area, dividing it into a series of parallel ridges with steep stony areas forming the canyon walls. The rainfall in this area increases with elevation, resulting in soils of 114 University of California — Experiment Station much greater depth and with much greater natural cover at the higher elevations than at the lower elevations. All of the alluvial soil of the area, of which there is only about 1,000 acres, is included in one type, the Honcut loam. The residual soils (group VI) include the Aiken and Olympic series from basic igneous material; the Holland and Sierra series from granitic material; the Diamond Springs series from quartz porphyry ; the Sites from sandstones ; and the Mariposa from shales. Livestock is the principal industry of the area, although pears are grown extensively on the better soils, particularly the deep phase of the Aiken clay loam, and peaches are produced on the Holland loamy sand. Most of the fruits are irrigated. Table 48 shows the soil group, index rating, and grade for each type of soil found in the Soil Survey of the Placerville Area. 46 This survey covers 371,200 acres, of which more than 38 per cent are nonarable on account of rough, steep topography and rockiness. None of the soils are rated as grade 1 ; only 15,872 acres are in grade 2, and 86,848 acres are in grade 3. The location of the various grades of soil in the Placerville area may be found in area 40 on map 1. 46 Storie, E. Earl, and D. F. Trussell. Soil survey of the Placerville area, Cali- fornia. U. S. Dept. Agr. Bur. Chem. and Soils, Ser. 1927, Rept. 34:1-35. Bul. 599] A Rating of California Soils 115 TABLE 49 Bed Bluff Area : Eating of Soils in Accordance with the Storie Index Soil type* Redding loam Redding gravelly sandy loam.. Corning loam Corning loam, sandy phase Corning gravelly loam Tehama gravelly loam Tehama silt loam Tehama clay May wood loam May wood fine sandy loam May wood gravelly sandy loam Maywood silt loam May wood silty clay loam Kirkwood silty clay adobe Tuscan stony sandy loam Tuscan stony loam Elder gravelly fine sandy loam Elder silt loam Elder silty clay loam Vina fine sandy loam Vina fine sandy loam, gravelly phase Vina loam Vina loam, deep silty phase Vina clay loam Vina clay adobe Sacramento fine sand Sacramento fine sandy loam.... Sacramento silt loam Sacramento silty clay loam Riverwash Rough stony land Soil group IV IV III III III II II II I I I I I III V V I I I I I I I I I I I I VII VII Factors, per cent 25 25 40 40 40 85 85 85 95 95 95 95 95 80 20 20 100 100 100 100 100 100 100 100 100 100 100 100 100 100 65 100 100 70 70 100 60 100 100 65 100 90 70 65 70 70 100 90 100 70 100 100 85 70 65 100 100 90 75 100 90 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 80 80 100 100 100 Index per cent 16 36 36 25 59 85 51 95 95 62 95 86 56 13 14 70 100 90 100 70 60 100 85 56 52 100 100 90 Grade Remarks Av. depth V/2 ft. ; puddles very badly Av. depth VA ft. Compact gravelly subsoils; sur- face irregular Texture variable ; surface irregu- lar Shallow; hog-wallow surface Texture variable May have hardpan Drainage somwhat restricted locally Surface and subsoil variable Surface and subsoil variable Gravel content variable Very stony and shallow Very stony and shallow May have stratified subsoil May have stratified subsoil Variable Usually underlain with gravel; not typical of series Poorly drained Subject to overflow; not typical of Sacramento in later areas Surface sometimes irregular ; subject to overflow; not typ- ical of Sacramento in later Surface irregular; may be sub- ject to overflow; not typical of Sacramento in later areas Nonagricultural Nonarable * The names given to some of the soil series in the older areas (Red Bluff, 1910) may not conform to later correlations and the rating values should not be confused with those for soils having similar names in other areas. 41. RED BLUFF AREA The Red Bluff area is located in Tehama and Butte counties near the northern end of the Sacramento Valley. The area includes the valley floor and the low terrace lands bordering it on both the east and west 116 University of California — Experiment Station sides. The climate is typical of the interior valley, except that the rain- fall is somewhat heavier than at points farther south. No group-VI soils are mapped in this area. The Tuscan series is a group-V soil with a dense rock-like substratum. The Redding series is a hardpan soil (group IV), and the Corning and Kirkwood soils are in group III. The Tehama series is normally in group II but as mapped in this area has a compact subsoil approaching a hardpan in places. The Maywood, Elder, Vina, and Sacramento series are group-I soils and show only slight indications of weathering. The group-I soils are used extensively for fruit, alfalfa, and other irrigated crops, while the other soils are used for grain or pasture. Table 49 shows the soil group, index rating, and grade for each soil type found in the Soil Survey of the Bed Bluff Area. 4 " 1 This survey in- cludes 208,640 acres, of which 99,840 acres are in grade 1 ; 5,248 acres in grade 2 ; and 12,928 acres in grade 3. The location of the various grades of soil in the Red Bluff area may be found in area 41 on map 1. 47 Holmes, L. C, and E. C. Eckmann. Soil survey of the Eed Bluff area, Cali- fornia. U. S. Dept. Agr. Bur. Soils, Field Oper. 1910:1601-56. (Out of print.) Bul. 599] A Rating of California Soils 117 42. REDDING AREA The Redding area is located in Shasta County, and includes that por- tion of the upper Sacramento Valley known as Anderson Valley. This is a region of relatively high rainfall, practically all of which occurs in the winter. The Belle vista (group V) and Redding (group IV) series of soils occur on gently rolling terraces lying above the valley floor. The Ander- TABLE 50 Bedding Area: Eating of Soils in Accordance with the Storie Index Soil type* Soil group Factors, per cent Index per cent Grade Remarks A B C Redding gravelly loam IV IV II II V I I I I VII VII 30 20 80 80 40 100 100 100 100 70 100 70 100 100 65 100 100 100 80 80 100 90 100 100 100 100 100 17 16 56 72 40 65 100 100 100 1 2 5 5 3 2 3 2 1 1 1 6 6 Av. depth to hardpan 3 ft. ; Redding loam eroded Av. depth 2 ft. ; eroded Anderson gravelly loam Anderson fine sandy loam Bellevista sandy loam Somewhat eroded Texture and subsoil vary widely Sacramento gravelly sandy loam Texture variable; often excess- Sacramento fine sandy loam.... Sacramento silt loam ively gravelly; not typical of Sacramento in recent areas Surface uniform; subsoil var- iable; not typical of Sacra- mento in recent areas Friable; not typical of Sacra- Sacramento loam mento in recent areas Uniform; well drained; not typ- Riverwash ical of Sacramento in recent areas Nonagricultural Rough stony land Nonarable * The names given some of the soils in the older areas (Redding, 1907) may not conform to later corre- lations, and the rating values should not be confused with those for soils having similar names in other son (group II) and Sacramento (group I) series occupy low, flat valley floor positions. Alfalfa, fruit, and general farm crops are grown under irrigation, and grain and hay are grown without irrigation. Pasture is the only use for the poorer soils. Table 50 gives the soil group, index rating, and grade of each soil type found in the Soil Survey of the Redding Area. 48 This survey covers 128,000 acres, of which 18,432 acres are in grade 1 ; 8,384 acres in grade 2 ; and 17,856 acres in grade 3. The location of the several grades of soil in the Redding area may be found in area 42 on map 1. 48 Lapham, M. H., and L. C. Holmes. Soil survey of the Eedding area, California. U. S. Dept. Agr. Bur. Soils, Field Oper. 1907:973-99. (Out of print.) 118 University of California — Experiment Station TABLE 51 Eiverside Area : Eating of Soils in Accordance with the Storie Index Soil type Soil group Factors, per cent Index per cent Grade Remarks Holland sandy loam Holland loam Sierra loam Altamont clay loam Placentia gravelly loam Placentia sandy loam Placentia loam Placentia loam, hardpan phase Placentia clay loam Madera sandy loam Ramona sandy loam Ramonaloam Ramona clay loam Ramona clay loam (A) Antiochloam Antioch silty clay loam Montezuma silty clay loam Hanford stony sandy loam Hanford gravelly sand Hanford gravelly sandy loam. . Hanford gravelly loam Hanford sand Hanford sand, coarse phase Hanford sand, wind-blown phase Hanford coarse sandy loam Hanford sandy loam... Hanford sandy loam (A) Hanford sandy loam, reddish- brown phase Hanford fine sandy loam Hanford fine sandy loam (A).... Hanford fine sandy loam, red- dish-brown phase Hanford loam Hanford loam, reddish-brown phase Hanford silty clay loam Hanford silty clay loam, red- dish-brown phase Hanford silty clay loam, red- dish-brown phase (S) Tujunga stony sand VI VI VI VI III III III IV III IV II II II II III III III I I I I I 70 70 70 65 60 60 60 20 60 25 85 85 85 85 50 50 70 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 95 100 100 85 70 95 100 100 85 95 95 100 85 85 100 90 90 65 40 65 70 60 30 30 90 95 95 95 100 100 100 100 100 90 90 90 15 80 85 85 100 100 100 100 100 100 100 100 100 50 100 100 100 80 100 100 100 90 100 100 100 100 40 80 100 40 100 100 100 100 60 40 53 60 60 55 42 57 60 20 41 24 81 85 72 36 50 45 63 52 40 65 70 54 30 30 90 95 38 76 100 40 100 100 100 90 54 36 14 Av. depth to bedrock over 3 ft. ; erosion active Av. depth to bedrock over 3 ft. ; erosive; sometimes steep Depth and texture vary ; av. depth over 3 ft. ; erosive Depth and texture vary; av. depth over 3 ft. Subsoil density variable Subsoil density variable Subsoil density variable Hardpan at 2 ft. Uneven topography; drainage poor Av. depth to hardpan 2)4 ft. Alkali or poor drainage Texture and profile extremely variable Texture and profile extremely variable May be very stony ; leachy Leachy In places practically free from gravel Subject to wind movement in places Coarse sand ; leachy Coarse; uneven topography Alkali Drainage fair Deep; friable Alkali Typical except in color Deep; friable Typical except in color Poorly drained in places Alkali in small areas Very stony and leachy Bul. 599] • A Rating of California Soils TABLE 51 — Eiverside Area — (Concluded) 119 Soil type Tujunga gravelly sand Tujungasand Tujunga sand, low phase Tujunga fine sandy loam Chino silt loam Chino silt loam (A) Chino silt loam, sandy phase.. Chino silty clay loam Yolo gravelly loam Yolo gravelly loam, high-fan phase Yolo loam Yolo silty clay loam Yolo silty clay loam, high-fan phase Oakley sand „ Riverwash Rough broken land Rough stony land Soil group II I VII VII VII Factors, per cent 100 100 100 100 95 95 95 100 90 100 100 90 100 25 60 90 100 100 100 100 90 70 70 100 90 90 90 40 90 80 50 80 60 100 100 100 100 100 50 Index per cent 100 90 Grade Remarks Leachy Wind erosion active Poorly drained Poorly drained in places Drainage fair Alkali Fine sandy loam ; drainage fair Drainage fair to poor; alkali in places Not typical of series Not typical of series Loamy sand; wind-blown Nonagricultural Nonarable Nonarable 43. RIVERSIDE AREA The Riverside area lies in western Riverside and San Bernardino coun- ties, and comprises the eastern part of what is known as the "Valley of Southern California." It consists of a number of alluvial fans extending from the surrounding mountains and merging into a gently sloping plain east and southeast of Ontario. A few extremely stony mountains occur in the vicinity of Riverside. The climate is distinctly semiarid, with a rainfall ranging from about 10 to 20 inches a year. The recent alluvial soils of group I are included in the Hanford, Tu- junga, Chino, Yolo, and Oakley series. The soils of group II include the Ramona series and the high fan phases of the Yolo series. Soils of group III include the Placentia, Antioch, and Montezuma series. The Madera series and the hardpan phase of Placentia loam are in group IV. The residual soils (group VI) include the Holland and Sierra series from granitic material and the Altamont series from mixed sedimentary rocks. About 15 per cent of the total is nonagricultural on account of topography or stoniness. The general climatic and soil conditions in this area are favorable to a wide range of intensively cultivated crops. Citrus and deciduous fruits, walnuts, alfalfa, and many truck and vegetable crops are grown under irrigation. Water is expensive and is therefore used economically. 120 University of California — Experiment Station Alkali is not prevalent in the Kiverside area but certain spotted areas are indicated by the symbol S, and stronger concentrations by the symbol A. Table 51 shows the soil group, index rating, and grade of each soil type found in the Soil Survey of the Riverside Area.* 9 This survey covers 387,840 acres, of which 87,104 acres are in grade 1 ; 80,032 acres in grade 2 ; and 119,808 acres in grade 3. The location of each grade of soil in the Riverside area may be found in area 43 on map 4. 49 Nelson, J. W., et al. Soil survey of the Kiverside area, California. U. S. Dept. Agr. Bur. Soils, Field Oper. 1915:1-88. 1917. Bul. 599] A Rating of California Soils 121 TABLE 52 Salinas Area: Rating of Soils in Accordance with the Storie Index Soil type Soil group Holland coarse sandy loam. Kettleman loam Diablo clay Santa Lucia clay loam Santa Lucia clay loam, heavy phase Moro Cojo loamy sand Tierra sandy loam Chamise sandy loam Gloria sandy loam Placentia sandy loam Chualar sandy loam Chualarloam Lockwood gravelly sandy loam Lockwood gravelly sandy loam, heavy phase Montezuma clay loam adobe... Montezuma clay loam adobe, silty phase Antioch fine sandy loam Rincon very fine sandy loam... Rincon very fine sandy loam, heavy phase Elkhornsand Elkhorn sand, shallow phase. McClusky sandy loam McClusky sandy loam, shal- low phase Greenfield sand Greenfield sand, gravelly phase Greenfield coarse sandy loam. Greenfield fine sandy loam Greenfield fine sandy loam, gravelly phase Salinas fine sandy loam Salinas fine sandy loam, non- calcareous phase Salinas fine sandy loam, heavy phase Salinas fine sandy loam, over wash phase Salinas very fine sandy loam... Salinas silty clay loam Salinas clay Marina sand Hanfordsand Hanford fine sand. VI VI VI VI VI VI V V IV III II II III III III III III II III II II III VI Factors, per cent 100 100 100 100 100 95 95 95 95 95 95 95 95 100 100 90 100 60 85 60 80 95 95 95 95 95 100 65 70 85 100 100 100 55 90 100 70 100 100 100 100 100 90 60 60 65 100 90 90 100 100 80 80 70 90 90 100 100 100 100 90 95 90 90 100 70 90 100 100 100 100 100 100 100 100 100 100 100 100 90 100 100 Index per cent 46 49 54 63 57 77 47 57 40 51 34 60 55 90 100 70 95 95 95 95 95 86 57 51 60 65 Grade Remarks 3J^ to 5 ft. deep Av. depth 2 ft.; low in humus; somewhat erosive 3 to 5 ft. deep ; low in humus V/i ft. deep Av. depth 2 ft. ; clay Deep; badly eroded Eroded Shallow; eroded Shallow; eroded Erosive Compact subsoil Compact subsoil Somewhat eroded Somewhat eroded Clay and silty clay ; subsoil more dense than typical for series 2 to 4 ft. deep Acid; subdrainage poor Rock at 40 in. ; not typical of series Includes variations in texture Friable and deep Friable; high in humus Loam Metz over Salinas Porous ; somewhat infertile Leachy ; resembles riverwash in places Overflowed in places 122 University of California — Experiment Station TABLE 52 — Salinas Area — {Concluded) Soil type Hanf ord very fine sandy loam Metz fine sand Metz fine sand, loamy phase... Metz fine sandy loam Metz very fine sandy loam Metz loam Metz silty clay loam Dublin clay adobe Dublin clay adobe, clay-loam phase Alvisoclay Tidal marsh Peat Peat Coastal beach and dunesand... Rough mountainous land Riverwash Soil group Factors, pei cent Index per cent Grade A B C 1 100 100 100 100 1 I 100 65 50 33 4 I 100 90 50 45 3 I 100 100 100 100 1 I 100 100 70 70 2 I 100 100 100 100 1 I 100 90 100 90 1 I 100 70 100 70 2 I 100 85 100 85 1 I 100 50 5 3 6 VII 2 6 I 20 4 I 72 2 VII 1 6 VII 3 6 VII 1 6 Remarks Overflowed Loamy fine sand; overflowed Fertile Gullied by overflow Drainage poor in some areas Not typical of series Alkali strong Nonagricultural Undrained areas Drained areas Nonagricultural Nonarable Nonagricultural 44. SALINAS AREA The Salinas area is located in northern Monterey County, and includes the northern part of the Salinas Valley with the adjoining terrace, foot- hill, and mountain lands. The rainfall in this area decreases with dis- tance from the ocean, from about 17 inches at Monterey to less than 10 inches at Soledad. Summer temperatures are modified by breezes from the ocean. The group-I soils are represented by the Hanford, Metz, Dublin, and Alviso series, occupying bottom lands, and the Greenfield and Marina series, occupying terraces slightly above the river floodplains. The group-II soils include the Chualar, Salinas, Rincon, and Elkhorn series. The group-Ill soils include the Placentia, Lockwood, Montezuma, Anti- och, and McClusky series and the heavy phase of Rincon, and the hardpan soils of group IV, the Gloria series ; the soils of these two groups occupy valley slopes and terraces, which are often badly eroded and in some places are hilly. In group V are the Tierra and Chamise soils, which have dense clay subsoils that rest on consolidated material and usually occupy high eroded terraces. The residual soils (group VI) include the Holland, Kettleman, Diablo, Santa Lucia, and Moro Co jo series and occur in the hilly or mountainous parts of the area where the slope, depth, and degree of erosion varies considerably. Peat occurs in the northwestern part of the area. In general, the intensive agriculture of the area is confined to the Bul. 599] A Rating of California Soils 123 recent and young alluvial soils, where sugar beets, lettuce, artichokes, alfalfa, and similar crops are grown under irrigation. In years of ample rainfall, dry-farmed grain is grown on the better of the higher-lying lands. The climate is well suited to the production of most field and truck crops. A strong wind movement in the upper part of the area and fog along the coast limits the production of fruits to protected localities. Table 52 shows the soil group, index rating, and grade for each soil type found in the Soil Survey of the Salinas Area. 50 This survey covers 488,960 acres, of which 78,784 acres may be classed as grade-1 soils, 85,696 acres as grade-2 soils, and 121,088 acres as grade-3 soils. One- third of the area is nonagricultural. The location of the various grades of soil in the Salinas area may be found in area 44 on map 3. so Carpenter, E. J., and Stanley W. Cosby. Soil survey of the Salinas area, Cali- fornia. U. S. Dept. Agr. Bur. Chem. and Soils, Ser. 1925, Eept. 11:1-80. 124 University of California — Experiment Station TABLE 53 San Fernando Valley Area : Eating of Soils in Accordance with the Storie Index Soil type Holland stony loam Holland coarse sandy loam.. Holland loam Altamont clay loam. Sites sandy loam.. Diablo clay loam. » Diablo clay adobe Ramona stony sandy loam. Ramona sandy loam.. Ramona fine sandy loam Ramona loam Hanford stony sandy loam Hanford gravelly sandy loam. Hanford loamy coarse sand Hanford sandy loam Hanford finesandy loam Hanford silt loam Tujunga stony sand Tujunga gravelly sand.. Tujunga sand Tujunga sandy loam Tuj unga fine sandy loam.. Yolo gravelly loam Yolo gravelly sandy loam Yolo sandy loam Yolo fine sandy loam Yolo loam Yolo silt loam Yolo clay loam Yolo silty clay loam Dublin loam Dublin clay loam.. D ubli n clay loam , brown phase Dublin clay adobe Rough broken land Rough stony land Riverwash Soil group VI II III I VII VII VII Factors, per cent 85 SO 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 65 100 100 85 65 95 100 100 65 70 60 95 100 100 15 25 95 100 70 70 95 100 100 100 85 90 100 85 85 60 80 90 90 100 100 100 100 40 90 95 70 30 100 100 100 100 100 100 100 90 90 100 100 100 100 100 100 100 100 90 100 100 Index per cent 36 22 76 56 20 70 60 95 100 100 15 25 54 86 90 70 70 95 100 100 100 85 90 Grade Remarks Steep; very stony Av. depth 2 ft. ; may be rather steep Av. depth 2)4, ft. ; erosive Av. depth 2J/6 ft.; texture var- iable 2]/ 2 ft. deep 2H ft. deep; includes areas of Altamont 3 to 4 ft. deep; some areas rather steep Gravelly stony subsoils; includes areas of Holland Some areas have very compact subsoil Slightly eroded; drainage poor at certain seasons Eroded Verystony; leachy; low in humus Leachy Very coarse and leachy ; over- flowed Very coarse and leachy; over- flowed Leachy subsoils Texture variable Drainage sluggish ; may be grav- elly in subsoil Drainage sluggish; resembles Yolo in places More typical of Antioch Nonarable Nonarable Nonagricultural Bul. 599] A Rating of California Soils 125 45. SAN FERNANDO VALLEY AREA The San Fernando Valley area is located in the western part of Los Angeles County just north of the City of Los Angeles. It includes the San Fernando Valley and a narrow rim of the surrounding hilly or mountainous land. Most of the valley land is made up of recent alluvial soils, group I, comprising the Hanford, Tujunga, Yolo, and Dublin series. Except where the texture is too stony, gravelly, or sandy, these are all of high value for a wide range of crops. Small areas of alluvial terraces occur along the rim of the valley which are mapped as the Ramona series, group II. The residual soils of group VI are represented by the Holland, Altamont, Sites, and Diablo series, and occupy the hill lands along the edge of the valley. The climate is favorable for the growth of a wide range of orchard and truck crops. Water is supplied from the Los Angeles Aqueduct for irri- gation. The use made of the soils in the San Fernando Valley has been governed by urban conditions and the availability of irrigation rather than by the character of the soil. Large quanties of fertilizers are used, and most of the area is owned in small units. Table 53 shows the soil group, index rating, and grade for each soil type found in the Soil Survey of the San Fernando Valley Area. 51 This survey covers 175,360 acres, of which 71,808 acres are in grade 1 ; 18,240 acres in grade 2 ; and 24,192 acres in grade 3. The location of each grade of soil in the San Fernando Valley area may be found in area 45 on map 4. 51 Holmes, L. C, et al. Soil survey of the San Fernando Valley area, California. U. S. Dept. Agr. Bur. Soils, Field Oper. 1915:2451-507. (Out of print.) 126 University of California — Experiment Station 46. SAN JOSE AREA The San Jose area is located in Santa Clara County, and includes the lower end of the Santa Clara Valley. The climate of the region is char- acterized by a wet and a dry season with moderate rainfall during the winter months. Temperatures are moderate throughout the year. The area covered by the soil survey includes only secondary soils. The Placentia series represents the most fully weathered soil of the area (group III), and the Salinas and San Joaquin series have moderately TABLE 54 San Jose Area : Eating of Soils in Accordance with the Storie Index Soil type* Soil group Factors, per cent Index per cent Grade Remarks A B C I III I I II II I I VII 100 80 95 100 80 80 100 100 70 95 100 85 90 60 60 100 100 100 90 80 100 100 10 80 70 76 86 68 72 48 6 80 2 2 2 1 2 2 3 6 1 6 may be gravelly May be poorly drained or grav- elly Not typical of series typical of series * Names given to some of the soil series in the older areas (San Jose, 1903) may not conform to later correlations and the rating values given should not be confused with those for soils having similar names in other areas. developed profiles (group II). The more recent deposits (group I) are mapped as Arroyo Seco, Oxnard, Galveston, and Fresno series. This survey was made during the early years of soil-survey work and. the series names used at that time do not conform to those used in more recent surveys. This region is used extensively for deciduous fruits, truck crops, and grain. Table 54 shows the soil group, index rating, and grade for each soil type found in the Soil Survey of the San Jose Area. 52 This survey covers 200,320 acres, of which 9,408 acres are in grade 1 ; 134,336 acres in grade 2 ; and 30,400 acres in grade 3. The location of the different grades of soil in the San Jose area may be found in area 46 on map 3. 62 Lapham, Macy H., et al. Soil survey of the San Jose area, California. U. S. Dept. Agr. Bur. Soils, Field Oper. 1903:1183-217. (Out of print.) Bul. 599] A Rating of California Soils 127 TABLE 55 San Luis Obispo Area : Bating of Soils in Accordance with the Storie Index Soil type Los Osos fine sandy loam Los Osos gravelly clay loam Los Osos loam Los Osos loam, gravelly phase Los Osos clay loam Arnold sandy loam Arnold sandy loam, reddish- brown phase Arnold sandy loam, heavy- textured phase Cayucos clay adobe Cayucos gravelly loam Zaca clay loam, brown phase... Zaca gravelly clay loam adobe Yolo loam Yolo loam, poorly drained phase Elder fine sandy loam Dublin fine sandy loam Dublin clay adobe Metz fine sandy loam Metz fine sandy loam, heavy- textured phase Metz loam Agueda fine sandy loam Agueda clay loam Agueda clay loam adobe, poorly drained phase Elkhorn loamy sand Bay wood fine sand Botella clay loam Botella clay loam, light-tex- tured phase Clear Lake fine sandy loam Clear Lake clay loam Clear Lake clay adobe Hames fine sandy loam Hames clay loam Hames clay loam, heavy-tex- tured phase Hames clay loam, dark-colored gravelly phase Lockwood gravelly fine sandy loam Lockwood gravelly fine sandy loam, dark-colored phase Lockwood gravelly fine sandy loam, dark heavy-textured Soil group Factors, per cent Index per cent Grade A B C VI 60 100 90 54 3 VI 60 70 90 38 4 VI 60 100 SO 54 3 VI 50 70 100 35 4 VI 60 85 100 51 3 VI 50 95 70 33 4 VI 40 95 80 30 4 VI 50 100 80 40 3 VI 60 70 100 42 3 VI 40 70 80 22 4 VI 60 85 100 51 3 VI 60 80 100 48 3 I 100 100 90 90 1 I 100 100 70 70 2 I 100 100 90 90 1 I 100 100 100 100 1 I 100 60 100 60 2 I 100 100 100 100 1 I 100 85 100 85 1 I 100 100 100 100 1 I 100 100 95 95 1 I 100 85 100 85 1 I 100 70 60 42 3 II 90 80 80 58 3 I 95 65 60 37 4 I 95 85 100 81 1 I 95 100 100 95 1 I 95 100 90 86 1 I 95 85 100 81 1 I 95 60 100 57 3 III 80 100 90 72 2 III 80 85 100 68 2 III 80 60 100 48 3 III 80 55 90 40 3 III 70 70 100 49 3 III 80 70 100 56 3 III 80 55 100 44 3 Remarks %Y 2 to 4 ft. deep Includes some Santa Lucia 2Y 2 ft. deep Includes shallower Olympic and Konokti 3 ft. deep; very erosive Av. depth 2 ft. ; resembles Moro Cojo; very erosive Hilly; fine sandy loam to clay loam; erosive Eroded ; not typical of series 3 ft. deep 3 ft. deep Occasionally subject to overflow High water table in winter High water table in winter Some areas poorly drained Clay loam Overflowed at times May contain alkali Subdrainage restricted Acid; eroded Acid; infertile; wind-blown Loam Drainage somewhat restricted Erosive Clay Eroded Includes some more recent non- typical material 128 University of California — Experiment Station TABLE 55 San Luis Obispo Area — (Concluded) Soil type Soil group Factors, per cent Index Grade Remarks A B C per cent II III III III VII VII VII VII VII 80 60 80 65 65 100 70 85 70 100 100 100 36 60 56 55 8 5 3 3 3 4 2 3 3 6 6 6 6 6 Erosion active McClusky finesandy loam Heavy compact subsoil Montezuma clay adobe, Not typical of series; clay loam Rough mountainous land Rough broken and stony land Coastal beach and dunesand ... surface Nonarable Nonarable Nonagricultural Nonagricultural Nonagricultural 47. SAN LUIS OBISPO AREA The San Luis Obispo area is located in western California about midway between San Francisco and Los Angeles. The major part of the area lies in San Luis Obispo County and a small part in Santa Barbara County. There is a wide range of climatic, topographic, and physio- graphic features found in this area, and consequently a large number of soil series and types. The residual soils (group VI) include members of the Los Osos, Ar- nold, Cayucos, and Zaca series. There are no group-IV and group-V soils in the area, but there are four series with heavy compact subsoils (group III) — the Hames, Lockwood, McClusky, and Montezuma se- ries. The Elkhorn and Garey series have moderately developed subsoils (group II) ; and the Yolo, Elder, Dublin, Metz, Agueda, Bay wood, Botella, and Clear Lake series are in group I. Except where poor drainage or heavy textures interfere, all of the recent alluvial soils are fertile and productive ; beans, alfalfa, barley and a variety of truck crops are produced. The soils having compact subsoils are used for beans, grain, and grazing, while most of the residual soils are devoted to grain or grazing, or are in native cover. Stock rais- ing is an important industry in this area. Table 55 gives the soil group, index rating, and grade for each soil type found in the Soil Survey of the San Luis Obispo Area. 53 This sur- vey covers 469,760 acres, of which about 64 per cent are nonagricul- tural on account of topography or stoniness. Of the remainder, 28,992 acres are in grade 1 ; 12,544 acres in grade 2 ; and 96,768 acres in grade 3. The location of the grades of soil found in the San Luis Obispo area may be found in area 47 on map 3. 53 Carpenter, E. J., and R. Earl Storie. Soil survey of the San Luis Obispo area, California. U. S. Dept. Agr. Bur. Chem. and Soils, Ser. 1928, Rept. 29:1-60. Bul. 599] A Rating of California Soils 129 TABLE 56 Santa Maria Area : Rating of Soils in Accordance with the Storie Index Soil type Soil group Factors, per cent Index per cent Grade Remarks A B C Arnold sandy loam VI VI VI VI VI VI VI VI II II III IV IV IV II III VII VII VII 40 25 40 60 60 40 60 70 80 80 80 40 40 40 85 70 95 95 95 100 100 100 100 100 100 100 100 100 100 100 100 100 100 95 60 65 55 85 70 85 60 100 100 100 60 95 100 100 70 60 65 100 65 60 65 95 95 100 100 90 100 100 85 60 40 70 80 80 80 80 80 100 80 85 80 80 80 100 90 100 80 100 90 90 100 80 80 80 100 100 100 100 100 80 90 80 70 80 80 30 12 21 26 41 28 41 36 64 64 64 24 34 40 68 49 51 56 95 52 48 52 95 95 100 100 90 80 90 68 42 32 56 50 1 1 3 4 5 4 4 3 4 3 4 2 2 2 4 4 3 2 3 3 3 1 3 3 3 2 3 4 3 3 6 6 6 tility low Very shallow; rock outcrop; erosion active Altamont fine sand Altamont gravelly clay loam... Erosion active; 3 to 5 ft. deep Diablo gravelly loam 2 ft. deep; rock outcrop; includes Diablo clay loam adobe areas of Climax Olympic clay adobe includes Altamont Pleasanton fine sandy loam Pleasanton loam elly clay and rock outcrop Erosive Pleasanton silt loam Madera sand contain hardpan areas 4 ft. to hardpan 4 ft. to hardpan ; erosive Madera sandy loam Madera loam Garey fine sandy loam wallowy Montezuma clay adobe Oakley sand humus Dune topography Dune topography Oakley fine sand Yolo sand Yolo fine sand Yolo sandy loam Yolo sandy loam, heavy phase Yolo finesandy loam Yolo silt loam Dublin finesandy loam Drainage poor in many places Dublin loam Drainage poor in places Drainage poor Dublin clay Drainage poor Dublin gravelly clay adobe Dublin clay adobe Drainage generally poor in sub- soil Drainage poor Peat Riverwash Nonagricultural Coastal beach and dunesand.... Rough broken and stony land Nonagricultural Nonarable 48. SANTA MARIA AREA The Santa Maria area is located in the northwestern part of Santa Bar- bara County and southwestern San Luis Obispo County. The Santa Maria Valley and territory both to the north and south are included. 130 University of California — Experiment Station This is a region of moderate rainfall and mild temperature. Most of the rain falls during the winter months, and frequent fogs reduce the sum- mer temperature. The hilly areas bordering the main valley are composed of group-VI soils of the Arnold, Altamont, Diablo, and Olympic series. The Madera soils of group IV, the Montezuma soils of group III, and the Pleasanton and Garey soils of group II occupy elevated terrace positions between the hill and the valley lands. The Oakley, Laguna, Yolo, and Dublin se- ries of group I occupy the flat valley areas. The soils of the Dublin series are generally poorly drained, while those of the Oakley series have rough sand-dune topography. Erosion is active on the Altamont, Arnold, and Garey soils. The well-drained valley soils of this area are intensively farmed to alfalfa and annual crops, such as beans, beets, vegetables, and flower seeds. The terrace soils are farmed to grain, beans, and peas, while the residual soils are devoted chiefly to pasture and range production. Table 56 gives the soil group, index rating, and grade for each type of soil found in the Soil Survey of the Santa Maria Area. 54 This survey covers 189,440 acres, of which 38,976 acres are in grade 1 ; 13,952 acres in grade 2 ; and 69,120 acres in grade 3. About one-sixth of the area is nonagricultural on account of topography or the excessively sandy na- ture of the soil. The location of the various grades of soil in the Santa Maria area may be found in area 48 on map 3. 54 Watson, E. B., and Alfred Smith. Soil survey of the Santa Maria area, Cali- fornia. U. S. Dept. Agr. Bur. Soils, Field Oper. 1916:1-48. 1919. Bul. 599] A Rating of California Soils 131 TABLE 57 Santa Ynez Area: Eating of Soils in Accordance with the Storie Index Soil type Soil group Factors, per cent Index per cent Grade Remarks Metz silty clay loam Metz silty clay loam, heavy- textured phase Metz silty clay loam, poorly drained phase Metz very fine sandy loam Metz very fine sandy loam, heavy-textured phase Metz fine sand w Ballard fine sandy loam Ballard fine sandy loam, friable-subsoil phase Botellaloam Botella fine sandy loam Botella sandy loam Botella sandy loam, poorly drained phase Botella clay Salinas gravelly loam Salinas gravelly clay loam Salinas clay Elder fine sandy loam Elder fine sandy loam, grav- elly phase Elder gravelly clay Elder sandy loam Elder sandy loam, gravelly phase Agueda sandy clay Agueda sandy clay, heavy phase Agueda sandy clay loam Agueda clay adobe Cachuma gravelly fine sandy loam Cachuma fine sandy loam. Zacaclay Altamont fine sandy loam Altamontclay Altamont clay, dark heavy phase Tierra fine sandy loam Tierra fine sandy loam, light- colored phase Tierra clay loam Arnold fine sandy loam Arnold sand Santa Lucia clay Santa Lucia clay, gravelly phase I I I I II I I I I I I II II II I I I I I I I I I III III VI VI VI VI V V V VI VI VI VI 100 100 100 100 100 100 90 95 95 95 95 95 95 95 95 95 100 100 100 100 100 100 100 100 100 90 65 85 100 100 65 100 100 100 100 95 95 60 70 65 60 100 70 70 95 70 70 60 85 70 70 100 50 100 50 50 100 100 85 100 70 50 35 100 100 60 100 100 100 100 100 100 100 100 40 100 100 100 100 90 100 100 100 100 100 100 100 100 90 100 100 80 75 SO 100 100 90 51 100 100 Texture variable Silty clay to clay High water table More silt than typical Not typical of the series Drainage poor Subject to occasional overflow Subject to occasional overflow Not very gravelly Clay or clay loam Drainage in subsoil poor during winter Drainage in subsoil poor during winter 3 ft. deep; rock fragments 3 ft. deep; erosive Similar to Diablo soils Shallow; erosive Shallow; erosive Shallow; erosive 32 to 45 in. deep; erosion active Erosion active 35 to 45 in. deep Contains nontypical material 132 University of California — Experiment Station TABLE 57 — Santa Ynez Area — (Concluded) Soil type Montezuma clay Santa Ynez fine sandy loam Laguna clay loam Laguna fine sand Yolo fine sandy loam Yolo fine sand Marina sand Tangairsand Tangairsand, heavy-subsoil phase Chamise gravelly fine sandy loam Chamise gravelly fine sandy loam, light-colored phase Peat Rough broken land Coastal beach and dunesand... Riverwash Soil group I IV IV V I VII VII VII Factors, per cent 70 70 100 95 100 100 95 35 35 30 45 60 70 85 65 100 65 100 100 100 90 100 90 70 100 80 100 Index per 42 49 85 56 100 59 40 21 17 17 32 60 5 1 1 Grade Remarks 50 to 70 in. to substratum 45 to 56 in. to substratum May contain gravel Wind-eroded Somewhat eroded; not typical of series Drainage restricted Shallow ; eroded Drainage poor Nonarable Nonagricultural Nonagricultural 49. SANTA YNEZ AREA The Santa Ynez area is located in western Santa Barbara County. The area includes the Santa Ynez Valley, the Los Alamos Valley, and the bordering hills. This is a region of mild summer and winter climate and moderate rainfall. Most of the rain falls during the winter months. Fre- quent fogs temper the summer climate. The topographic and geologic features of the area are so varied that a rather large number of soil con- ditions are found. In group VI, the residual soils, occupying the hill areas, are the Zaca, Altamont, Arnold, and Santa Lucia series. The Tierra and Chamise se- ries are old terrace soils developed on consolidated substrata and are in group V. The Tangair series is in group IV. Also occupying terrace positions but at slightly lower elevations are the group-Ill soils of the Cachuma, Montezuma, and Santa Ynez series. The group-II soils of the Ballard and Salinas series occupy positions only slightly above the flood plain. The remaining soils of the area are all in group I and show prac- tically no weathering. They occupy low flat flood-plain positions and are locally subject to poor drainage and occasional overflow. These soils are mapped as the Metz, Botella, Elder, Agueda, Laguna, Yolo, and Ma- rina series and the friable-subsoil phase of Ballard. The valley soils are used extensively for a wide variety of annual crops, including vegeta- bles, beans, beets, and flower seeds. Beans, grain, and hay are produced Bul. 599] a Rating of California Soils 133 on the terrace soils. Hay and pasture are the principal uses for the re- sidual soils. Table 57 gives the soil group, index rating, and grade for each type of soil found in the Soil Survey of the Santa Ynez Area. 55 This survey covers 482,560 acres, of which more than 40 per cent are nonagricultural because of topography or excessive sandiness. Of the remaining area, 72,576 acres are in grade 1 ; 29,056 acres in grade 2 ; and 60,416 acres in grade 3. The location of the several grades of soil found in the Santa Ynez area may be found in area 49 on map 3. ss Carpenter, E. J., T. W. Glassey, and E. Earl Storie. Soil survey of the Santa Ynez area, California. U. S. Dept. Agr. Bur. Chem. and Soils, Ser. 1927, Kept. 15:1-48. 134 University of California — Experiment Station TABLE 58 Shasta Valley Area: Eating of Soils in Accordance with the Storie Index Soil type Altamont loam Altamont loam, shallow phase Lassen loam Lassen clay loam Lassen clay loam, red phase Lassen clay adobe Shasta gravelly sand Delaney gravelly sand Delaney gravelly finesand Delaney fine sandy loam Corning gravelly loam Agate gravelly loam Agate sandy loam Agate sandy loam, gravelly phase Montague clay loam adobe Pinole gravelly loam Bellevista loam Bellevista clay Hoveyloam Gazelle loam Gazelle loam, sandy phase Gazelle clay loam Elder gravelly sandy loam Elder gravelly sandy loam, light-textured phase Elder fine sandy loam Elder loam Elder loam, gravelly phase Dublin clay loam Sutter fine sandy loam Sutter fine sandy loam, light- textured phase Vina sandy loam Vina sandy loam, light-tex- tured phase Vina fine sandy loam Vina fine sandy loam, heavy phase Conejo fine sandy loam.. Conejo fine sandy loam, heavy phase Conejo clay loam Conejo clay loam, gravelly phase Soil group Factors, pei cent Index per cent Grade A B C VI 40 100 90 36 4 VI 25 100 90 23 4 VI 40 100 90 36 4 VI 25 85 90 19 5 VI 40 85 90 31 4 VI 40 70 90 25 4 II 85 20 100 17 5 I 100 15 100 15 5 I 100 40 100 40 3 I 100 100 80 80 1 III 70 70 90 44 3 IV 20 70 100 14 5 IV 20 95 100 19 5 IV 15 65 100 10 5 IV 30 85 100 26 4 III 80 70 100 56 3 IV 15 100 80 12 5 IV 15 50 70 5 5 II 80 100 70 56 3 IV 35 100 80 28 4 IV 15 95 80 11 5 IV 25 85 80 17 5 I 100 75 100 75 2 I 100 40 100 40 3 I 95 100 80 76 2 I 100 100 100 100 ! I 100 70 100 70 2 I 100 85 90 77 2 I 100 100 60 60 2 I 100 70 60 42 3 I 100 95 50 48 3 I 100 50 70 35 4 I 100 100 100 100 1 I 100 100 100 100 1 I 100 100 100 100 1 I 100 100 50 50 3 I 100 85 50 43 3 I 100 55 100 55 3 Remarks 2 ft. deep ; erosion active 1 ft. deep; steep; erosion active 2 ft. deep; rock outcrop in places 1 ft. deep; rock outcrop in places 2 ft. deep 2 ft. deep Low moisture-holding capacity Loose; porous; low in humus Gravelly subsoils Large cobblestones in subsoil; erosive Hardpanatl8to20in. Hardpan at 16 to 30 in. Hardpan usually at 10 to 16 in. Hardpan at about 3 ft. Gravel may be absent Alkali-spotted; hardpan at 6 to 20 in. Drainage poor; hardpan at 6 to 24 in. Eroded ZYl ft. to hardpan ; alkali-spotted Hardpan at shallow depths ; alkali-spotted Hardpan at shallow depths; alkali-spotted Fine sandy loam subsoil Coarse sand and gravel Drainage usually poor; contains nontypical areas Some areas have been mined Contains considerable gravel Drainage fair Rests on bedrock Rests on bedrock Rests on bedrock at 3 ft. or less Rests on bedrock 6 ft. or more deep Loam surface; clay loam subsoil May be gravelly in places Subject to overflow; drainage poor Subject to overflow; drainage poor Bul. 599] A Rating of California Soils TABLE 58 — Shasta Valley Area — {Concluded) 135 Soil type Soil group Factors, pei cent Index Grade Remarks A B C per cent 1 I VII VII VII 100 70 60 42 40 5 3 3 3 3 6 6 6 Subject to overflow; drainage Muck and peat poor Drainage poor Tailings Nonarable Scabland Nonarable Rough broken and stony land Nonarable 50. SHASTA VALLEY AREA The Shasta Valley area lies just south of the California-Oregon state line in Siskiyou County. This area embraces the Shasta Valley and ad- jacent mountain lands. This is a region of moderate rainfall, which oc- curs mostly during the winter months. The summers are dry and warm, and the winters cold. A considerable portion of the moisture comes as snow. The floor of Shasta Valley has an elevation of 2,500 to 3,000 feet, and the survey includes elevations to about 4,000 feet. Frosts may occur within the area any month of the year. The soils of this area are generally shallow and those on the valley floor poorly drained. The parent material of the region is, for the most part, of volcanic origin, although sedimentary rocks, including sand- stones, shales, and conglomerates, do occur in association with the ig- neous material. The Altamont series from sedimentary rocks, and the Lassen series from igneous rocks represent the group-VI soils. The Agate, Montague, Bellevista, and Gazelle series are in group IV. The Corning and Pinole series are group-Ill soils, and the Shasta and Hovey series group-II soils. The soils of the Delaney, Elder, Dublin, Sutter, Vina, and Cone jo series are all in group I but they may not be so deep as they are found typically in other areas. Grain, hay, and pasture grasses are the principal products of the soil, for stock raising is the main agricultural industry of the region. Table 58 gives the soil group, index rating, and grade for each soil type found in the Soil Survey of the Shasta Valley Area. 56 This survey covers 327,680 acres, of which more than half is nonagricultural on ac- count of topography or stoniness. Of the remaining area, 8,640 acres are in grade 1 ; 17,408 acres in grade 2 ; and 28,992 acres in grade 3. The location of the different grades of soil in the Shasta Valley area may be found in area 50 on map 1. se Watson, E. B., M. E. Wank, and Alfred Smith. Soil survey of the Shasta Valley area, California. U. S. Dept. Agr. Bur. Soils, Field Oper. 1919:99-152. 1923. 136 University of California — Experiment Station 51. STOCKTON AREA The Stockton area lies in the lower part of the San Joaquin Valley and embraces the valley land in the vicinity of the City of Stockton in San Joaquin County. This is a region of low rainfall and moderate to high temperatures. Only flat valley areas are included in this survey. There are, there- fore, no primary or group-VI soils represented. The soil survey of this TABLE 59 Stockton Area : Eating of Soils in Accordance with the Storie Index Soil type* Soil group Factors, per cent Index per cent Grade Remarks A B C IV IV IV I I IV II I II IV IV II I 20 25 35 100 100 60 90 100 90 60 40 80 100 95 100 60 65 95 100 100 85 70 85 85 100 100 100 100 100 100 100 100 100 100 80 100 20 24 35 60 65 57 90 100 77 42 27 68 80 4 4 4 2 2 3 1 2 3 4 2 Av. depth V/i ft. Hardpan at V/% ft. Fresno fine sand typical of the series May contain alkali; no hardpan; Fresno sandy loam not typical of the series Hardpan at about 5 ft.; may Stockton loam contain alkali Stockton loam adobe 6 ft. ; not typical of the series clay loam texture; may con- tain alkali ; not typical of series Hardpan at 6 ft. or more; may be alkaline; not wholly typical of the series Hardpan at about 4 f t. ; drainage poor; may be alkaline Stockton clay loam adobe Peat Depth and drainage variable * Names given to some of the soil series in the older areas (Stockton, 1905) may not conform to later correlations and the rating values given should not be confused with those for soils having similar names in other areas. area was made at a time when the correlation of soil series was not so complete as is now maintained, and soils of varying degrees of develop- ment are included in a single series. A portion of this area is covered by the more recent Lodi area, table 34. In the hardpan soils, group IV, are the San Joaquin and certain members of the Fresno and Stockton series. Other members of the Fresno and Stockton series, as well as the Sacra- mento series, are included in groups I or II. Drainage is deficient in both the Fresno and the Stockton series, and alkali occurs in places. Bul. 599] a Rating of California Soils 137 Climatic conditions are such that a relatively wide variety of crops is produced, including deciduous fruits, alfalfa, beans, truck, and grain. Table 59 gives the soil group, index rating, and grade for each soil type found in the Soil Survey of the Stockton Area. 57 This survey covers 333,248 acres, of which 150,272 acres are in grade 1 ; 61,312 acres in grade 2 ; and 46,784 acres in grade 3. The location of the different grades of soil in the Stockton area may be found in area 51 on map 2. 57 Lapham, Macy H., and W. W. Mackie. Soil survey of the Stockton area, Cali- fornia. U. S. Dept. Agr. Bur. Soils, Field Oper. 1905:997-1031. (Out of print.) 138 University of California — Experiment Station TABLE 60 Suisun Area : Eating of Soils in Accordance with the Storie Index Soil type Konokti stony clay loam Konokti stony clay loam, shallow phase Los Osos clay loam Los Osos clay loam, steep phase Los Osos clay adobe Hugo sandy loam Hugo clay loam Hugo clay loam, steep phase.... Konokti, Los Osos, and Hugo soils, undifferentiated steep phase Montezuma clay adobe Denverton clay adobe Denverton clay adobe, light- textured phase Yolo silty clay loam Yolo silty clay loam, poorly drained phase Yolo silty clay loam, calcareous phase Yolo silty clay loam, gray phase Yolo silty clay loam, dark- colored phase Columbia silty clay loam Conejo clay loam Esparto silty clay loam Esparto silty clay loam, light- textured phase Zamora fine sandy loam Zamora clay loam Capayloam Capay silty clay loam Capay silty clay loam, heavy- textured phase Lindsey clay loam Antioch fine sandy loam Antioch fine sandy loam, dark- colored phase Olcott fine sandy loam Olcott fine sandy loam, gray phase Olcott fine sandy loam, shal- low phase Solano finesandy loam Soil group VI VI VI VI VI VI VI VI VI III III III I I I I II II I I III III III III III III III III III III Factors, per cent 70 70 70 95 95 95 95 95 100 95 65 60 85 90 90 90 90 90 90 85 90 100 100 85 100 70 50 85 100 100 100 100 100 100 100 100 100 50 100 90 90 50 100 100 100 100 40 100 100 100 100 100 100 80 90 80 Index per cent 34 59 Grade Remarks Av. depth 30 in. 15 to 24 in. deep Steep and shallow 24 to 40 in. deep Shallow Steep and shallow Nonarable; soils having similar topography are mapped as rough mountain lands in other Friable Drainage poor; alkali Drainage sometimes poor Drainage poor Not typical of series Friable; some areas gravelly Fine sandy loam Friable Drainage variable Subsoil drainage usually poor Clay ; puddles badly Drainage poor ; alkali Drainage poor in winter; some alkali Drainage poor in winter Slight alkali Slight alkali Shallow Eroded; drainage poor Bul. 599] A Rating of California Soils TABLE 60— Suisun Area— (Concluded) 139 Soil type Solano fine sandy loam, hum- mock* phase Egbert loam Egbert loam, mucky phase Sacramento mucky loam Sacramento clay loam Clear Lake clay adobe Stockton clay adobe Muck and peat Marshland Marsh land, tidal phase Made land Soil group Factors, pei cent Index per cent Grade A B C III 40 100 40 16 5 I 100 100 80 80 1 I 100 100 80 80 1 II 90 100 80 72 2 II 90 60 80 43 3 II 95 60 90 51 3 V 40 60 100 24 4 I 60 2 VII 7 6 VII 7 6 VII 10 5 Remarks Very badly eroded Drainage somewhat restricted Drainage somewhat restricted Subdrainage often poor Drainage variable Drainage often poor Drainage moderate Drainage varies greatly Nonagricultural Nonagricultural Nonagricultural 52. SUISUN AREA The Suisun area covers the southern part of Solano County south of the north line of Township 5 North, M.D.M., and Grand and Sutter Islands lying in Sacramento County. This area lies in the zone of moderate rain- fall and moderate temperatures. The summers, although long and dry, are usually tempered by breezes from the Bay. Soils of the Konokti, Los Osos, and Hugo series (group VI) occur in the hilly and mountainous area west of the valley proper. These soils vary in depth and surface configuration, and are often steep. The un- differentiated types (Konokti, Los Osos, and Hugo soils, steep phase) consist of material approaching rough mountainous land. Soils of the valley plain vary from the recent alluvial soils of the Yolo, Columbia, Conejo, Zamora, and Egbert series (group I) to the older group III soils of the Montezuma, Denverton, Lindsey, Antioch, Olcutt, and So- lano series. The soils of the Esparto, Sacramento and Clear Lake series, which are of alluvial origin and slightly to moderately weathered, are placed in group II. Drainage is the controlling factor in the use of the soils on the flat, low-lying lands near the Sacramento River and the Bay. These are the Sacramento series of group II and the Egbert series and the muck and peat of group I. The crops in this area vary widely. Grain and pasture are produced on the flat valley soils, except those having high organic content, where asparagus, beets, beans, potatoes, and similar crops are grown. Decid- uous fruits are grown on the deep, alluvial, well-drained soils, as well as to a limited extent on the hill lands. Stock raising is an important industry in this area. 140 University of California — Experiment Station Table 60 gives the soil group, index rating, and grade for each soil type found in the Soil Survey of the Suisun Area. 58 This survey covers 352,000 acres, of which 49,344 acres are in grade 1 ; 54,144 acres in grade 2 ; and 138,368 acres in grade 3. The location of the various grades of soil in the Suisun area may be found in area 52 on map 1. * 58 Carpenter, E. J., and S. W. Cosby. Soil survey of the Suisun area, California. U. S. Dept. Agr. Bur. Chem. and Soils, Ser. 1930, Rept. 18:1-60. Bul, 599] A Rating of California Soils 141 TABLE 61 Ukiah Area : Eating of Soils in Accordance with the Storie Index Soil type Soil group Factors, per cent Index per Grade Remarks Mariposa loam Mariposa loam, deeper varia- tion Aiken stony loam Aiken loam Aiken loam, heavy phase Olympic stony loam Olympic loam Climax clay adobe Corning loam Corning gravelly loam Corning gravelly loam, eroded phase Corning gravelly clay loam Pleasanton gravelly loam Pinole sandy loam Pinole loam Pinole loam, eroded phase Pinole gravelly loam Pinole gravelly loam, eroded phase Yolo fine sandy loam, stream- bottom phase Yolo loam Yolo loam, stream-bottom phase Yolo gravelly loam Yolo gravelly loam, stream- bottom phase Yolo silt loam Yolo silt loam, stream-bottom phase Yolo silty clay loam Yolo silty clay loam, stream- bottom phase Tehama loam Tehama gravelly loam Tehama silt loam, poorly drained phase Honcut loam, red phase Honcut gravelly loam, red Dublin clay Riverwash Rough mountainous land.. VI VI VI VI VI VI VI VI III III III III II III III III III III I I VII VII 80 80 80 80 80 100 100 100 100 100 100 100 100 100 90 90 90 100 100 100 100 100 70 100 85 70 100 50 100 70 70 55 70 95 100 100 70 70 100 100 100 70 70 100 100 90 90 100 70 100 100 70 80 90 90 90 90 100 80 90 40 100 100 90 90 30 90 30 90 100 80 100 90 100 95 90 100 70 100 95 72 72 72 50 45 63 1 to 3 ft. deep; erosion active 3 to 6 ft. deep; erosion active 2 to 4 ft. deep; erosion active Av. depth 3 ft. ; erosion active 3 to 5 ft. deep; erosion active About 2 ft. deep; often steep; erosion active Av. depth 3H ft. ; erosion active 4 to 6 ft. deep Gravelly substratum Gravelly substratum Badly eroded; steep Deeper than typical Deeper than typical Leached soil; may contain gravel Leached Badly eroded Leached; drainage poor in de- pressions Badly eroded Texture variable ; may be subj ect to occasional overflow Texture and drainage variable Subject to occasional overflow; texture variable Subject to occasional overflow Drainage often poor Drainage often poor Low in humus ; mildly acid Large quantities of gravel; low in humus Texture variable Occasionally rests on compact subsoil at less than 6 ft.; not typical of series Occasionally has compact sub- soil at less than 6 ft. ; not typ- ical of series Drainage usually poor Nonagricultural Nonarable 142 University of California — Experiment Station 53. UKIAH AREA The Ukiah area embraces the arable valleys of the Russian River drain- age system in Mendocino County, together with the adjacent mountains. The valleys of this area lie at elevations ranging from 475 to 1,000 feet, and the adjacent mountainous area runs from 1,000 to 2,000 feet higher. The climate of this area is characterized by moderate to heavy rains in the winter and by dry summers of mild temperature. The hilly portions of this area are composed of group-VI soils of the Mariposa, Aiken, Olympic, and Climax series. Between the hill lands and the valley floors are two older terrace soils of group III, the Corn- ing and Pinole series ; and intermingled with them are two less fully de- veloped soils (group II) of the Pleasanton and Tehama series. The re- maining soils of the area are recent deposits (group I) mapped as Yolo, Honcut, and Dublin series. This group is often poorly drained, espe- cially during the winter months when the rainfall is heavy and the Russian River is at high stages. This region is highly developed to deciduous fruits, grapes, and grain. Alfalfa and hops are also grown on the deep alluvial soils near the river. Table 61 gives the soil group, index rating, and grade for each soil type found in the Soil Survey of the Ukiah Area. 59 This survey covers 193,920 acres, of which nearly 80 per cent are nonarable on account of steep topography. Of the remaining acreage, 13,632 acres are in grade 1 ; 9,728 acres in grade 2 ; and 17,216 acres in grade 3. The location of the different grades of soil in the Ukiah area may be found in area 53 on map 3. 59 Watson, E. B., and E. L. Pendleton. Soil survey of the Ukiah area, California. U. S. Dept. Agr. Bur. Soils, Field Oper. 1914:2629-77. (Out of print.) Bul. 599] A Rating of California Soils 143 TABLE 62 Ventura Area : Eating of Soils in Accordance with the Storie Index Soil type Altamont stony loam Altamont loam Altamont loam, gravel sym- bols* Altamont loam, light-textured phase Altamont clay loam Altamont clay adobe Diablo clay adobe Olympic loam Olympic loam, gravel sym- bols* Olympic loam, stony phase Olympic clay adobe Olympic clay adobe, light- textured phase Rincon fine sandy loam Rincon fine sandy loam, coarse phase Rincon loam Rincon loam, silty phase Rincon loam, calcareous phase Rincon clay loam Pleasanton gravelly sandy loam Pleasantcn gravelly sandy loam, stone symbols* Pleasanton gravelly loam Pleasanton loam Ojai very fine sandy loam Madera sandy loam Montezuma clay adobe Yolo gravelly fine sandy loam.. Yolo sand Yolo fine sand Yolo fine sand (S) Yolo fine sand (A) Yolo sandy loam Yolo sandy loam (S) Yolo sandy loam, gravel symbols* Yolo fine sandy loam Yolo finesandy loam (S) Yolo fine sandy loam (A) Yolo very finesandy loam Soil group VI VI VI VI VI VI VI VI VI VI VI VI II II II III II III II II II II II IV III I I I I I I I I I I I I Factors, per cent 60 70 100 100 100 100 100 100 100 100 100 100 100 100 70 100 70 100 85 60 70 100 70 70 70 70 100 100 100 100 85 65 65 70 100 100 90 70 70 65 65 65 95 95 70 100 100 100 100 90 90 90 90 100 70 70 50 70 80 70 50 80 70 60 100 100 100 100 60 10 100 100 100 10 100 Index per cent 48 32 54 54 27 49 42 25 14 34 38 56 50 64 48 64 48 39 28 48 60 51 27 56 70 48 65 39 7 95 57 70 100 60 10 100 Grade Remarks 1 to 4 ft. deep; erosion active 3 ft. or more deep; erosion active Gravelly areas Includes fine sandy loam and coarse sandy loam 3 to 6 ft. deep; erosive 2 to 3 ft. deep ; erosive Wt. to i}4 ft. deep 1 to 6 ft. deep; steep and erosive Shallower and more gravelly than typical 2 ft. deep; stony ; steep areas 3 ft. deep; erosive Silty; erosive Erosive; variable Erosive; variable; coarse sandy loam Erosive; variable Subsoil and topography ex- tremely variable; erosive Subsoil variable; erosive Variable; erosive Eroded Eroded; very stony Erosive Erosive Gravelly subsoil; low water- holding capacity Hardpan at 2 to 4 ft. ; erosion active Eroded in places Texture variable Subsoil texture and drainage variable; subject to overflow Alkali-spotted Strong alkali Deep; friable Alkali-spotted Variable in gravel content Alkali-spotted Strong alkali * Areas where the soil survey indicates, by symbols, the presence of gravel or stone, but which are not described as a separate soil type. 144 University of California — Experiment Station TABLE 62 — Ventura Area — (Concluded) Soil type Yolo very fine sandy loam (S).. Yolo very fine sandy loam (A) Yolo loam Yolo loam (S) Yolo loam (A) Yolo silt loam Yolo silt loam (S) Yolo silt loam (A) Yolo silty clay loam Yolo silty clay loam (S) Yolo silty clay loam (A) Dublin loam Dublin loam (S) Dublin loam (A) Dublin clay loam Dublin clay loam (S) Dublin clay loam (A) Dublin clay loam, adobe phase Dublin clay loam, adobe phase (S) Vina fine sandy loam Riverwash Rough broken and stony land Coastal beach and dunesand Tidal marsh Soil group VII VII VII VII Factors, per cent 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 90 90 90 100 100 100 85 85 85 70 70 100 60 10 100 60 10 100 60 10 100 60 10 70 50 7 70 50 Index per cent 60 10 100 60 10 100 60 10 90 54 9 70 50 7 60 43 7 56 35 70 1 5 Grade Remarks Alkali-spotted Strong alkali Alkali-spotted Strong alkali Alkali-spotted Strong alkali Alkali-spotted Strong alkali Drainage fair Alkali-spotted Strong alkali Drainage restricted Alkali-spotted Strong alkali Drainage fair Alkali-spotted Some gravel and stone; shallow areas Nonagricultural Nonarable Nonagricultural Nonagricultural 54. VENTURA AREA The Ventura area is located in southwestern California and includes most of the southern half of Ventura County. Nearly all of the agricul- tural land of the county is included in the survey, together with consid- erable interlying mountain areas. Elevations in the area range from sea level to more than 6,300 feet. The climate is characteristic of the south- ern coast, with low to moderate rainfall coming mostly during the win- ter, and temperatures which are moderated by local fogs both summer and winter. The hilly areas are composed of residual soils (group VI) those from sedimentary rocks represented by the Altamont and Diablo series, and from basic igneous rocks by the Olympic soils. The Madera series is the only one mapped which has a hardpan (group IV), but the Montezuma and certain types of the Eincon have dense clay subsoils (group III) . In group II, those soils having moderately dense subsoils include the Rin- con, Pleasanton, and Ojai series. The Yolo, Dublin, and Vina series Bul. 599] A Rating of California Soils 145 represent the most recent alluvial deposits of group I. Alkali is an impor- tant factor in the Yolo and Dublin soils, and different ratings have been given the soils of these two series on the basis of their alkali content, S indicating slight amounts or spotted alkali, and A indicating strong concentrations. The soils and climatic conditions in this area are such that a wide va- riety of crops are grown, among which are citrus fruits, deciduous fruits, alfalfa, walnuts, beans, and beets, under irrigation, with grain and hay usually grown without irrigation. Table 62 gives the soil group, index rating, and grade of the several types of soil found in the Soil Survey of the Ventura Area. 60 This sur- vey covers 728,960 acres, of which more than 57 per cent are nonarable on account of topography and stoniness. A large percentage of the re- mainder is in the higher grades (1, 2, and 3), but data are not available on the areal distribution of alkali, so that the acreage in each grade is not known. The location of the various grades of soil found in the Ventura area may be found in area 54 on map 4. so Nelson, J. W., et al. Soil survey of the Ventura area, California. U. S. Dept. Agr. Bur. Soils, Field Oper. 1917:1-89. 1920. 146 University of California — Experiment Station TABLE 63 Victorville Area: Eating of Soils in Accordance with the Storie Index Soil type Mojavesand Mojavesand, caliche phase Mojaveloam Mojaveloam, playa phase Adelanto sand. Adelantosand, rolling phase... Adelanto loamy sand Adelanto loamy sand, rolling phase Adelanto sandy loam Adelanto sandy loam, rolling phase Adelanto loamy sand, heavy phase Sunrise sand Sunrise sandy loam Sunrise sandy loam, rolling phase Sunrise sandy loam, eroded phase Hesperiasand Hesperia loamy sand Hesperia loamy flnesand Hanford coarse sand Hanford very fine sand Foster fine sand Foster silt loam Cajon coarse sand Cajon coarse sand, loamy phase Cajon coarse sand, dark- colored phase Cajon loamy fine sand Dunesand Riverwash Rough stony land Rough broken land Soil group Factors, per cent Index per cent Grade A B C III 70 60 90 38 4 IV 20 80 90 14 5 III 70 90 90 57 3 III 70 85 20 12 5 III 70 60 100 42 3 III 70 60 40 17 5 III 70 80 90 50 3 III 70 80 30 17 5 III 70 85 90 54 3 III 60 95 30 17 5 III 70 85 50 30 4 IV 35 60 100 21 4 IV 35 95 100 33 4 IV 35 95 40 13 5 IV 35 95 40 13 5 I 95 60 90 51 3 I 95 80 90 68 2 I 95 90 90 77 2 I 100 30 90 27 4 I 100 80 100 80 1 I 100 65 100 65 2 I 100 100 65 65 2 I 100 30 80 24 4 I 100 40 80 32 4 I 100 65 90 59 3 I 100 90 80 72 2 VII 8 6 VII 5 6 VII 3 6 VII 5 6 Remarks Low in humus ; leachy Lime hardpan 2 to 2J^ feet Low in humus Clay loam; lake beds; drainage very poor Dune surface Low in humus Dune topography Eroded; dune topography Clay loam texture Av. depth to hardpan 3H ft. Av. depth to hardpan 2 to 5 ft. Eroded; essentially nonagricul- tural Eroded; essentially nonagricul- tural Low in humus Low in humus Low in humus Leachy ; low in humus Alkali in places Drainage poor ; some alkali Subject to overflow Subject to overflow Not typical of Cajon series Nonagricultural Nonagricultural Nonarable Nonarable 55. VICTORVILLE AREA The Victorville area is located on the Mojave Desert in San Bernardino County, and includes the region in the vicinity of Victorville, and east and south of this town. The climate is extremely arid, and the summers are very hot. Winter temperatures are mild. All of the soils of this area are secondary, although some of them have fully developed profiles. The group-IV soils are mapped as Sunrise, and Bul. 599] A Rating of California Soils 147 a caliche phase of Mojave series. In group III are found the Mojave and Adelanto series. In group I, the recent unweathered deposits, are found the Hesperia, Hanford, Foster, and Cajon series. The sandy types of all of the soils in this region have been modified by wind to the extent that much of the surface has the sand-dune type of relief. Irrigation is required for all crops, and only those of highest value are under cultivation. The water supply is limited. Alfalfa and forage crops are the principal products raised, although apples are produced in favored localities. Table 63 gives the soil group, index rating, and grade for each type found in the 8 oil Survey of the Victorville Area. Gl This survey covers 226,560 acres, of which only 1,024 acres, represented by one soil type, are in grade 1 ; 52,864 acres are in grade 2 ; and 89,280 acres in grade 3. The location of the several grades of soil in the Victorville area may be found in area 55 on map 4. si Kocher, A. E., and Stanley W. Cosby. Soil survey of the Victorville area, California. U. S. Dept. Agr. Bur. Soils, Field Oper. 1921:623-72. 1924. 148 University of California — Experiment Station TABLE 64 Visadia Area: Eating of Soils in Accordance with the Storie Index Soil type* Soil group Factors, per cent Index per cent Grade Remarks A B C VI VI VI VI VI I I I I I I I I I I I I I I I I I II I I I I I I I I I I I I I I I 45 20 35 30 70 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 95 100 90 100 100 100 100 100 100 100 100 100 100 100 100 100 95 95 95 70 55 50 60 80 20 95 95 95 95 100 60 100 95 65 100 100 85 60 70 95 100 95 90 90 90 100 100 100 95 100 100 100 100 100 100 100 100 100 100 70 100 70 60 90 100 95 60 60 30 65 100 30 80 70 80 90 80 100 100 70 80 64 40 100 75 35 100 100 75 50 20 100 90 72 43 14 19 11 42 56 12 86 95 90 57 60 18 65 95 20 80 70 68 54 53 95 90 67 72 58 36 100 75 35 95 100 75 50 20 100 86 68 3 5 5 5 3 3 5 1 1 1 3 2 5 2 1 4 2 2 3 3 1 2 2 3 4 2 4 1 1 2 3 4 2 Vista sandy loam, rock-out- out stones Tujunga loamy sand, gravelly Visalia sandy loam, San- Visalia fine sandy loam, San- Rests on San Joaquin at 3 to 5 ft. Visalia sand, San-Joaquin- Rests on San Joaquin at 2 to 3 ft. Visalia fine sandy loam, Honcut sandy loam, gravelly Some erosion Honcut loam, calcareous- sub- Sometimes contains alkali Some erosion Surface undulating Greenfield sandy loam, heavy- Greenfield sandy loam, shal- Hardpan at 2 to 4 ft. Slight alkali Cajon sandy loam (M) Moderate alkali Deep; friable Cajon finesandy loam (S) Cajon finesandy loam (M) Slight alkali Moderate alkali Foster finesandy loam Deep; friable Foster fine sandy loam (S) Foster finesandy loam, Spotted alkali Fresno hardpan at 2 to 3 ft. Foster fine sandy loam, Fresno-subsoil phase (S) Hardpan 2 to 3 ft. ; slight alkali Drainage fair Chino finesandy loam (S) Slight alkali * The correlation of the soils of this area has not been made and name sand types given are subject to change. Bul. 599] A Rating of California Soils TABLE 64 — Visalia Area — (Concluded) 149 Soil type* Chino fine sandy loam, coarse- textured phase Chino loam Chino loam (S) Chino clay loam Chino clay Traver sandy loam (S) Traver sandy loam (M) Traver sandy loam (A) Traver sandy loam, fine- textured phase Traver sandy loam, solonetz phase Porterville adobe clay Porterville adobe clay, stony phase Hovey adobe clay Merced clay loam Dinuba sandy loam Dinuba sandy loam (S) Dinuba sandy loam (M) Exeter loam Exeter loam, heavy-textured phase Exeter loam, gravelly phase San Joaquin sandy loam San Joaquin loam San Joaquin clay loam Yokohlloam Yokohlclay Madera sandy loam Madera loam Madera loam (S) Madera loam (M) Madera clay loam Seville adobe clay Lewis fine sandy loam (A) Lewis fine sandy loam (S) Lewis clay loam Fresno fine sandy loam Rough stony land Riverwash Soil group Factors, per cent Index per cent Grade A B C I 95 85 90 73 2 I 95 100 90 86 1 I 95 100 72 68 2 I 95 85 90 73 2 II 85 60 90 46 3 II 90 95 80 68 2 II 90 95 30 26 4 II 90 95 10 9 6 II 90 100 40 36 4 III 60 100 10 6 6 II 85 60 100 51 3 II 85 40 50 17 5 II 85 60 90 46 3 III 70 85 80 48 3 III 80 100 90 72 2 III 80 100 72 58 3 III 80 100 36 29 4 IV 60 100 100 60 2 IV 60 85 100 51 3 IV 70 90 100 63 2 IV 25 95 100 24 4 IV 25 100 100 25 4 IV 25 85 100 21 4 IV 20 90 100 18 5 IV 25 70 100 18 5 IV 50 95 100 48 3 IV 40 100 100 40 3 IV 40 100 80 32 4 IV 40 100 50 20 4 IV 40 85 100 34 4 IV 40 60 100 24 4 IV 40 100 10 4 6 IV 40 100 90 36 4 IV 40 85 10 3 6 IV 30 100 10 3 6 VII 2 6 VII 2 6 Remarks Course sandy loam Drainage fair Slight alkali Drainage fair Compact subsoil; drainage fair Slight black alkali Moderate alkali Strong alkali Moderate black alkali Strong alkali ; very compact Steep ; erosive Drainage restricted Drainage poor; Fresno substra- tum at 3 to 5 ft. Drainage fair Slight alkali Moderate alkali San Joaquin hardpan at 2 to 4 ft. Clay loam; San Joaquin hard- pan at 2 to 4 ft. Deep Hardpan at 2 to 3 ft. Hardpan at 2 to 3 ft. Hardpan at 2 to 3 ft. Hardpan at 18 to 24 in. Hardpan at 2 to 3 ft. Hardpan at 4 to 5 ft. Hardpan at 2 to 5 ft. ; includes areas with calcareous hardpan Slight alkali Moderate alkali Hardpan at 2 to 5 ft. Hardpan at V/i to ZYi ft. Strong alkali; hardpan at 3 to 5 ft. Slight alkali; not typical of series Strong alkali Strong alkali Nonarable Nonagricultural * The correlation of the soils o ithis area has not been made and names and types given are subject to change. 56. VISALIA ABEA The Visalia area covers the northern half of the west end of Tulare County, extending from the west boundary of the county eastward to include portions of the lower foothills. It lies in a region of low rainfall, 150 University of California — Experiment Station all of which occurs during the winter months. Summer temperatures are high. No crops without irrigation are grown. The field work of the soil survey of this area has been but recently completed and a final correlation of the soils has not yet been made. The names of soil types indicated in table 64 are preliminary only and subject to change. As mapped at the present time, the group-VI soils are included in the Vista, Las Posas and Lassen series ; the group-IV soils are included in the Exeter, San Joaquin, Yokohl, Madera, Seville, Lewis, and Fresno series ; the group-Ill soils are included in the Merced and Dinuba series and one member of the Traver series. In group II has been included the Traver, Porterville, and Hovey series, one type each of the Chino and Greenfield series. The Tujunga, Hanford, Visalia, Honcut, Delhi, Greenfield, Cajon, Foster, and Chino series are group-I soils. Alkali is a serious problem in certain areas and has been considered in the ratings. Three grades of alkali have been recognized, these being slight (S), moderate (M), and strong (A). There is a wide range of crops grown in this area : cotton, grain, hay, alfalfa, citrus, deciduous fruits, and truck crops, according to the loca- tion and availability of irrigation water. Table 64 shows the soil group, index value, and grade of each type of soil found in the Soil Survey of the Visalia Area. 62 Data are not avail- able on the areal distribution of the various soil types. The location of the various grades of soil in the Visalia area may be found in area 56 on map 2. 62 Storie, E. Earl, et al. Soil survey of the "Visalia area, California. U. S. Dept. Agr. Bur. Chem. and Soils. (In manuscript.) Bul. 599] A Rating of California Soils 151 57. WILLITS AREA The Willits is a small area covering the Little Lake Valley and the sur- rounding foothills in central Mendocino County. This is an enclosed valley in a region of high rainfall, the rains occurring in the winter and spring months. The hills surrounding the valley, occupied by grOup-VI soils, are made up of the Olympic soils from basic igneous rocks and Altamont soils from sedimentary rocks. The soils of the Willits and Kim- TABLE 65 Willits Area : Eating of Soils in Accordance with the Storie Index Soil type Soil group Factors, per cent Index per cent Grade Remarks A B c Olympic loam VI VI VI II II II I I I I I I VII 40 60 60 80 80 90 100 100 100 100 100 100 100 85 100 100 100 55 100 100 70 100 65 50 70 90 90 80 80 100 100 100 100 20 20 20 28 46 54 64 64 50 100 100 70 20 13 10 9 4 3 3 2 2 3 1 1 2 4 5 5 6 Olympic loam, red phase Altamont fine sandy loam Willits fine sandy loam numerous; unfavorable topog- raphy Belongs in Aiken series; clay- loam surface; steep; erosive 13^ to 5 ft. deep; somewhat erosive Willits fine sandy loam, heavy phase Kimball gravelly clay loam Yolo fine sandy loam Not typical of series Yolo loam Some areas subject to overflow Yolo loam, gravelly phase Wapato silt loam Gravelly loam soil Wapato silty clay Very poorly drained Wapato silty clay, heavy phase Rough montainous land Clay; very poorly drained Nonarable ball series are secondary and show slight to moderate degrees of weath- ering, and are classed as group-II soils. The soils of the Yolo and Wapato series are unweathered group-I soils. The lower part of Little Lake Valley, occupied by the soils of the Wapato series, is poorly drained and of use only for pasture. Hay, grain, and forage crops are grown on all of the valley soils where the drainage is good. The hilly areas are largely in timber and brush. Table 65 gives the soil group, index rating, and grade for each type of soil found in the Soil Survey of the Willits Area™ This survey covers only 19,200 acres, of which 36 per cent are rough mountainous land. Of the remainder, 4,736 acres are in grade 1 ; 3,776 acres in grade 2 ; and 1,088 acres in grade 3. The location of the several grades of soil in the Willits area may be found in area 57 on map 1. 63 Dean, W. C, Soil survey of the Willits area, California. TJ. S. Dept. Agr. Bur. Soils, Field Oper. 1918:1-32. 1920. 152 University of California — Experiment Station TABLE 66 Woodland Area : Eating of Soils in Accordance with the Storie Index Soil type Dunniganclay Dunnigan clay (B).. Dunnigan clay (C).. Dunnigan clay (D). Dunnigan clay (E).. Sacramento sand Sacramento sand (B) Sacramento fine sand Sacramento fine sandy loam. Sacramento silt loam Sacramento silt loam (B) Sacramento silt loam (C) Sacramento silty clay loam Sacramento silty clay loam (.B) Sacramento silty clay loam (C) Sacramento silty clay Sacramento silty clay (B) Sacramento silty clay (C) Sacramento silty clay (D) Sacramento heavy clay Sacramento heavy clay (B) Sacramento heavy clay (C) Sacramento heavy clay (D) Sacramento clay adobe Sacramento clay adobe (B) Sacramento clay adobe (C) Sacramento clay adobe (D) Yolo finesandy loam Yolo loam Yolo silt loam Yolo clay loam Yolo clay loam (B) Yolo clay loam (C) Yolo silty clay Yolo silty clay (B) Yolo clay Yolo clay (B) Yolo clay (C) Esparto loam Esparto clay loam Esparto clay Capay clay loam Capay clay Capay clay (B) Capay clay (C) Capay clay (D) Capay clay adobe Capay clay adobe (B) Capay clay adobe (C) Capay clay adobe (D) Soil group III III III III III I I I I I I I I I I II II II II II II II II II II II II I I I I I I I I I I I II II II III III III III III III III III III Factors, per cent 60 60 60 60 60 100 100 100 100 100 100 100 100 100 100 90 90 90 100 100 100 100 100 100 100 100 100 100 100 95 95 95 60 60 60 60 60 60 60 60 65 100 100 100 100 100 100 100 85 85 85 65 65 60 60 60 100 85 70 85 50 50 50 50 60 100 100 100 75 55 100 90 60 100 40 100 90 60 40 100 90 60 40 100 100 100 100 90 60 100 90 100 100 100 100 100 100 90 60 40 100 40 Index per cent 24 18 15 9 3 48 36 65 100 100 75 55 90 81 54 59 53 35 23 45 41 27 18 54 49 32 22 100 100 100 85 77 51 65 59 60 54 36 95 81 67 51 30 27 18 12 36 32 22 14 Grade Remarks Hog-wallow topography Slight alkali Moderate alkali Strong alkali Very strong alkali Loose, incoherent; should be Columbia Slight alkali Should be Columbia Should be Columbia; subsoil texture somewhat variable Should be Columbia Slight alkali Moderate alkali Should be Columbia Slight alkali Moderate alkali Slight alkali Moderate alkali Strong alkali Slight alkali Moderate alkali Strong alkali Slight alkali Moderate alkali Strong alkali Slight alkali Moderate alkali Slight alkali Slight alkali Moderate alkali Slight alkali Moderate alkali Strong alkali Slight alkali Moderate alkali Strong alkali BUD. 599] A EATING OF CALIFORNIA SOILS TABLE 66 — Woodland Area — (Concluded) 153 Soil type Arbuckle fine sandy loam Arbuckle gravelly sandy loam Arbuckle loam Arbuckle gravelly loam Arbuckle clay loam Willows loam Willows clay loam Willows clay Willows clay (B) Willows clay (C) Willows clay (D) Willows clay (E).. Willows clay adobe Willows clay adobe (B) Willows clay adobe (C) Willows clay adobe (D) Willows clay adobe (E) Sites silt loam Sites gravelly sandy loam Sites loam Sites clay loam adobe Sites clay adobe Riverwash Soil group I I I I I I II II II II II II II II II II II VI VI VI VI VI VII Factors, per cent 100 100 100 100 100 95 90 90 90 90 90 90 90 90 60 40 100 65 100 70 85 100 85 50 50 50 50 50 60 60 60 60 60 100 65 100 85 60 90 100 90 90 100 100 100 100 90 60 40 10 100 90 60 40 10 100 80 100 100 Index per cent Grade Remarks Gravelly ; subsoil variable Subsoil variable Drainage restricted in places Marsh Creek in recent surveys Drainage poor Slight alkali Moderate alkali Strong alkali Very strong alkali Drainage poor Slight alkali Moderate alkali Strong alkali Very strong alkali Subsoil variable, not typical of series ; erosive Conglomerate at 4 ft. ; erosive Conglomerate and gravel in sub- soil 18 to 30 in. to conglomerate 18 to 36 in. to conglomerate Nonagricultural 58. WOODLAND AREA The Woodland area is located near the southern end of the Sacramento Valley and west of the Sacramento River in Yolo and Colusa counties. This is a region of mild temperatures with dry summers and moderate to low rainfall in the winter. The area is bordered on the west by hills made up largely of group-VI soils of the Sites series, the result of residual weathering of shales and conglomerates. The Dunnigan, Capay, and Arbuckle series have dense clay subsoils and have been placed in group III. The Esparto and "Wil- lows series and the heavier members of the Sacramento series show slight to moderate weathering and have been placed in group II. The lighter members of the Sacramento (mapped as Columbia in more re- cent surveys) and the Yolo are recent deposits and are placed in group I. Grain, grapes, and deciduous fruits are grown extensively on the better soils of the area. Rice is grown on the heavier-textured valley soils where water is available for irrigation. Grain and grain hay are grown throughout the area. Alkali is an important consideration in this area, and the soil rating has taken this into account. Four degrees of 154 University of California — Experiment Station salinity are indicated ; B, slight (200 to 400 parts per 100,000) ; C, mod- erate (400 to 600 parts per 100,000) ; D, strong (600 to 1,000 parts per 100,000) ; and E, very strong (over 1,000 parts per 100,000). Table 66 gives the soil group, soil rating, and grade for each type of soil and degree of salinity found in the Soil Survey of the Woodland Area. 6 * This survey covers 656,000 acres, but data are not available on the areal distribution of alkali, and the acreage in the several grades of soil are therefore not given. The location of the several grades of soil in the Woodland area may be found in area 58 on map 1. s* Mann, C. W., et al. Soil survey of the Woodland area, California. U. S. Dept. Agr. Bur. Soils, Field Oper. 1909:1635-87. (Out of print.) Bud. 599] A Rating of California Soils 155 TABLE 67 Yuma-Wellton Area, Arizona-California: Eating of Soils in Accordance with the Storie Index Factors, per cent Index Soil type Soil group per cent Grade Remarks A B C Gila fine sandy loam 1 100 100 100 100 1 Alkali-free; depth variable Gila finesandy loam (S) 1 100 100 60 60 2 Slight alkali Gila finesandy loam (A) 1 100 100 20 20 4 Strong alkali Gila fine sandy loam, light- textured-subsoil phase I 100 100 90 90 1 Al kal i-f r ee ; 1 eachy s ubsoil Gila fine sandy loam, light- textured-subsoil phase (S).... I 100 100 54 54 3 Slight alkali Gila fine sandy loam, light- text ured-subsoil phase (A).... I 100 100 18 18 5 Strong alkali Gila very fine sandy loam I 100 100 100 100 1 Alkali-free; stratified subsoil Gila very finesandy loam (S).. I 100 100 60 60 2 Slight alkali Gila very finesandy loam (A).. I 100 100 20 20 4 Strong alkali Gila loam I 100 100 100 100 1 Alkali-free; stratified subsoil Gilaloam(S) I 100 100 60 60 2 Slight alkali Gila loam (A) I 100 100 20 20 4 Strong alkali Gila loam, light-text ured- subsoil phase I 100 100 90 90 1 Alkali-free; low moisture-hold- ing capacity Gila loam, light-text ured- subsoil phase (S) I 100 100 54 54 3 Slight alkali Gila loam, light-text ured- subsoil phase (A) I 100 100 18 18 5 Strong alkali Gila loam, heavy-textured- subsoil phase I 100 100 90 90 1 Alkali-free Gila loam, heavy-textured- subsoil phase (S) I 100 100 54 54 3 Slight alkali Gila silt loam I I 100 100 100 100 100 60 100 60 2 Alkali-free Gila silt loam (S) Slight alkali Gila silt loam (A) I 100 100 20 20 4 Strong alkali Gila clay loam I 100 85 100 85 Alkali-free Gila clay loam (S) I 100 85 60 51 3 Slight alkali Gila clay loam (A) I 100 85 20 17 5 Strong alkali Gila clay loam, light-textured phase I 100 85 70 60 2 Alkali-free; loose sandy subsoil Gila clay loam, light-textured phase (S) I 100 85 42 36 4 Slight alkali Gila clay loam, light-textured phase (A) I 100 85 14 12 5 Strong alkali Gilasilty clay loam I 100 90 100 90 Alkali-free; subsoil variable Gilasilty clay loam (S) I 100 90 60 54 3 Slight alkali Gila silty clay loam (A) I 100 90 20 18 5 Strong alkali Gila silty clay loam, light-tex- t ured-subsoil phase I 100 90 80 72 2 Alkali-free; somewhat leachy Gilasilty clay loam, light-tex- tured-subsoil phase (S) I 100 90 48 43 3 Slight alkali Gila silty clay loam, light-tex- tured-subsoil phase (A) I 100 90 16 14 5 Strong alkali Gila silty clay loam, heavy- textured-subsoil phase I 100 90 80 72 2 Alkali-free; drainage restricted Gila silty clay loam, heavy- textured-subsoil phase (S3).... I 100 90 . 48 43 3 Slight alkali 156 University of California — Experiment Station TABLE 67 — Yuma-Wellton Area — (Concluded) Soil type Gila silty clay loam, heavy- textured-subsoil phase (A).... Gila clay Gila clay (S) Gilaclay(A) Gila clay, light-textured- subsoil phase Gila clay, light-text ured- subsoil phase (S) Gila clay, light-text ured- subsoil phase (A) Gila clay, heavy-textured- subsoil phase Gila clay, heavy-textured- subsoil phase (S) Gila clay, heavy-text ured- subsoil phase (A) Gila fine sand Gila finesand (S) Gila finesand (A) Cajon loamy sand Cajon loamy sand (S) Cajon loamy sand (A) Alluvial soils, undifferentiated Dunesand Rough broken land Rough stony land Soil group VII VII VII Factors, per cent 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 90 60 60 60 16 100 80 20 90 54 18 80 64 16 80 48 16 60 36 12 Index per cent Grade Remarks Strong alkali Alkali-free Slight alkali Strong alkali Alkali-free ; leachy subsoil Slight alkali Strong alkali Alkali-free ; restricted drainage Slight alkali Strong alkali Alkali-free; infertile and leachy Slight alkali Strong alkali Alkali-free; subsoil variable Slight alkali Strong alkali Good land when protected from overflow Nonagricultural Nonarable Nonarable 59. YUMA-WELLTON AREA The Yuma-Wellton area lies in the extreme southeastern corner of Cali- fornia and in adjacent territory in Arizona. Only the portion of the area which lies in California is considered in this paper. This area lies in the Colorado Desert where the rainfall is very low and the summer temperatures hot. Irrigation must be supplied for all crops. All of the soils in this area are recent deposits from the Colorado River, and only two series were mapped : Gila, which has sixteen types, and Cajon, with one type. Alkali is an important consideration in this area and two degrees of salinity are recognized : S, slightly affected, and A, strongly affected. Alfalfa, cotton, and truck crops are grown in this area. Table 67 shows the soil group, soil rating, and grade for each type found in that portion of the Yuma-Wellton area 65 lying in California. 65 Youngs, F. O., et al. Soil survey of the Yuma-Wellton area, Arizona-California. U. S. Dept. Agr. Bur. Chem. and Soils, Ser. 1929, Eept. 20:1-37. Bul. 599] A Rating of California Soils 157 The California portion of this covers 26,422 acres, of which 17,384 acres are in grade 1 ; 2,911 acres in grade 2 ; and 3,424 acres in grade 3. The location of the different grades of soil in the Yuma-Wellton area may be found in area 59 on map 4. 10w-3,'36 n C^Cd| ■ s N I tmamm*/ W 5uS / m \ '^^v^ ''. / rJ / f£~~^ ■ A \ \ ' p--' > LI EUREKA AREA HUMBOLDT - B. & M. 43 1 1 \ \42 ! \fl I 1 SOIL CLASSIFICATION MISCELLANEOUS AREAS CALIFORNIA ,— u^ -r UNIVERSITY OF CALIFORNIA COLLEGE Or AGRICULTURE AGRICULTURAL EXPERIMENT STATION SOIL CLASSIFICATION UPPER SAN JOAQUIN VALLEY CALIFORNIA WALTER W. WEIR AND R. EARL STORIE DIVISION OF SOIL TECHNOLOGY, UNIVERSITY OF CALIFORNIA BASED ON SOIL SURVEYS MADE COOPERATIVELY BY UNITED STATES DEPARTMENT OP AOBICDLTURE, BUREAU OF CHEMISTRY AND SOILS, AND UNIVERSITY OF CALIFORNIA, DIVISION OF BOIL TECHNOLOGY MAPS COMPILED IN COOPERATION WITH DAVID WEEKS OF THE GIANNTNI FOUNDATION OF AGRICULTURAL ECONOMICS AND THE NATIONAL ] M -% \ j^ /, m t^^ 1SL M '% o 1M T 5 fctiM^ ?5 Q ^ uo /// ■^ &- -I? 'u. 1 / r s/V w IL SURVEY AREAS 13 CONCORD 18 FRESNO 27 LODI 29 MADERA 31 MERCED 32 MODESTO - TUR LOCK 51 STOCKTON R-l SACRAMENTO VALLEY RECONNOISSANCE R-4 MIDDLE SAN JOAQUIN VALLEY RECON. R-5 LOWER SAN JOAQUIN VALLEY RECON. KEY TO SOILGRADES (STOHIE INDEX RATING) S EXCELLENT RATING »0TO 'oYtT/ /An At /ERY POOR SOILS 1 I FT] POOR SOILS .J dwiversity or California OOLLBQE Or AGRI'IIJI.KJRE ITERIMENT STATION , CALIFORNIA SOIL CLASSIFICATION NORTH CENTRAL COAST CALIFORNIA WALTER W. WEIR AND E. EABT. ST0ED3 division of son. technolooy, university or California I HADE COOPERATIVELY BY UHITED STATES DEPARTMENT OP AGRICULTURE, BUREAU Or CHEMISTRY AND BOILS, AND UNIVERSITY OF CALIFORNIA, DIVISION OF SOIL TECHNOLOOY HAPS COMPILED IN COOPERATION WITH DAVTD WEEKS r THE OIANNDJI FOUNDATION OF AORIOULTUBAL AND THE NATIONAL REBOUROEB 13 CONCORD 14- DIXON §2!L SURVEY AREAS 13 CONCORD 14 DIXON 19 GILROY 21 HEALDSBURG 26 LI VERMORE 33 N A PA 36 PAJARO 46 SAN JOSE S2SUISUN [7] EXCELLENT SOILS AOBI"ULTURAfc JOIL CLASSIFICATIO SOUTHERN CALIFORNIA SOIL SURVEY AREAS 2 ANAHEIM S CAPISTRANO 15 EL CAJON 28 LOS ANGELES 34 OCEANSIDE 36 PASADENA 43 RIVERSIDE 45 SAN FERNANDO VAL. - — 44_VENTURA R-6 CENTRAL-SOUTHERN RECONNOISSANCE R-7 SAN DIEGO RECON- NOISSANCE KEY TO SOILGRADES (STORIE INDEX RAT RVILLE AREA ,N B.-B.8.M. 71 5 4