UNIVERSITY OF CALIFORNIA. 
 
 AGRICULTURAL EXPERIMENT STATION. 
 
 BULLETIN NO. 15. 
 
 As egards first, the mechanical nature of 
 these materials, it is striking that the harupn 
 subsoil contains so much less of inert sand than 
 the surface soil, although its aspect would lead 
 to the contrary conclusion. The hardpan is 
 considerably more retentive of moisture than 
 the surface soil, albeit the latter contains Borne 
 humus to increase this factor. The humus per- 
 centage of the soil is, however, very small, i.od 
 constitutes its chief defect, as in nearly all the 
 mesa soils of the southern region. The hardpan 
 stratum secures the land against waste of irri- 
 gation water, and against drought by its high 
 
 Examinations of Soils from Southern 
 California. 
 
 1.— Soils from Redlands Colony, 
 San Bernardino county. A set of soils reprt 
 senting this region was collected and sent by 
 Messrs. J. S. Edwards and E. G. Judson, oi 
 Redlands. The colony is situated on a stretch 
 of mesa at the head of Santa Ana valley, slop- 
 
 ing from the foothills to the samly valley land, reteut i vene8a Q f moisture 
 a distance varying from one to two miles, while Chemically, the surface soil is rich in potash 
 the mountains are about seven miles away. The (so heavily drawn upon by vines), while the 
 t i «mn l i^t a W( hardpan is relatively poor in that substance, 
 elevation ranges from 1,300 to 1,600 feet above ^ 1.^ percentag / ifJ £ he 8ame in Whf RDll U 
 
 sea level, the distance to the coa*t being about am pi e> Iu phosphoric acid, both ali e are above 
 50 miles. The sea breeze prevails in summer, j the limit of deficiency, but the supply is not 
 an east wind at night; light frosts in winter are large, and will probably be the first needing to 
 .... „ be replenished when the soil becomes "tired, 
 
 not severe enough to injure young orange trees. P £d pvrviousnes. of 
 
 There is little natural growth on the soil save long before this condition 
 
 alfi erilla and scattering clumps ot a low nrm-n. » . .. b . , 
 
 ' " ... ., 5 ..u ; „ ; , ^.iHioV, will make itself felt in the case of deep- rooted 
 
 The prevailing soil ot the region is a reddisn . . . A „ r 
 
 , r i l * • . „ ^ a A oi ,.f plants, such as vines and fruit trees. 
 
 brown, samly loam, containing a good deal ol i ' . , . , 
 
 coarse angular sand. This material changes Tw ° a, ts /""V 1 ,n . the 
 
 but slightly to the depth of from three to four e olo »y> differing from the one analyzed mainly 
 feet, « here it is mostly underlaid by an orange- la the greater proportion of sand, whirl, in one 
 yellow hardpan, flecked with white, the white ' 8 <»«*»• Jho latter Ovettt I the hardpan 
 spots being grains of coarse, angular sand, or to ^ de Pt" of [ our or hve feet, and is re- 
 rather, granitic debris, consisting mainly of V<>rted to have shown an especially thrifty 
 
 quartz and feldspar, with a little black horn 
 blende and magnetic iron ore ("black sand"). 
 This hardpan appears in gullies and ditches 
 everywhere, being usually mauy feet in thick- 
 ness. It is cmite porous, and its cement is a 
 red clay, which softens in water with little dif- 
 ficulty. Dry lumps can also be crushed between 
 the fingers, so that this subsoil may be consid- 
 ered as fairly penetrable by roots. Occasionally 
 this hardpan approaches the surface so closely 
 as to take direct part in the formation of the 
 soil. 
 
 The analyses of the soil and subsoil-hardpan 
 resulted as follows: 
 
 Red Soil. 
 
 12 ins. depth 
 No 728. 
 
 l ine Earth 57.9 
 
 Coarse Sand 42! 1 
 
 ANALYSIS OF FINE EARTH. 
 
 Insoluble Matter 69.56 ) S1 „ 67.14 ) 
 
 Soluble Silua 1182 j" 81 -" 18 10 sl r 
 
 P 0 ^ 1 ' .85 ' 
 
 Soda 
 
 Lime 
 
 Magnesia 
 
 Br. Oxide of Manganese. . . 
 
 Peroxide of Iron 
 
 Alumina 
 
 Phosphoric Acid. . 
 
 Sulphuric Acid ' . 
 
 Water and Organic Matter . 
 
 Hardpan 
 Subsoil. 
 3 to 4 feet. 
 No. 734. 
 
 81.2 
 
 18.8 
 
 .11 
 1.34 
 1.11 
 .08 
 3.46 
 8.87 
 .06 
 .01 
 2.60 
 
 77.95 
 
 .32 
 .40 
 1.44 
 2.58 
 .07 
 4.86 
 10.08 
 .06 
 .03 
 3.00 
 
 Humus 
 
 Available Inorganic ! ! 
 Hyeroscop. Moisture. 
 Absorbed at °C 12.0. 
 
 .37 
 .27 
 3.37 
 
 growth of the viues planted, though the latter 
 have done well on all. Prottably for the first 
 years at least, the thrift incKg of the viues will 
 be in direct proportion to the depth of the fur- 
 face layer of soil. 
 
 Soli from the Galon Valley, San Dletro Co 
 
 The Cajon valley, which has come into wider 
 notice only within a year or two, lies 1*4 miles 
 inland (east of) San Diego city, and may be ap- 
 proached either through Choya valley, or acre 
 the mesa; the highest elevation on the rout 
 being about 700 feet. The valley is of an ir 
 regularly rectangular shape, and is surround; 
 on all sides by hills, which on the north side 
 form a gradually ascending rolling country, 
 while elsewhere they are more abrupt; thus, 
 with the angular form of the valley, giving 
 rise to the name (signifying a box). The San 
 Diego river valley forms the northern edge and 
 the lowest portion of the plain, about 350 feet 
 above sea level ; from this there is ascent to 500 
 feet at the southern border, four miles away. 
 There is also a slight slope from the east and 
 west sides toward the center; the greatest 
 diameter in this direction being five miles. 
 
 Several smaller valleys, among thcmSvei- 
 more canyon, come from the sides, but none 
 of these have any permanent water way. 
 The river valley is well timbered wiHi willow, 
 sycamore, oak and coltonwood. The rest 
 the valley is treeless. 
 
 The prevailing soil outside of the river vail 
 is au orange or reddish brown, sandy lc 
 varying in depth from 20 inches to three f 
 
without sensible change, the Litter being the 
 more co-nrnon depth. The soil stratum is 
 underlaid by a more compact clayey material, 
 which however easily softens in water and is 
 readily worked when at all moist. ThiB 
 "hardpau," as it is sometimes c died, is from 15 
 to 25 teet in thickness, and is easily penetrated 
 by the roots of trees and vines. Beneath it 
 water is found in wells at depths varying from 
 seven feet at the north end to thirty feet 
 at the southern border. The water supply be- 
 ing about the same through the year, and, with 
 but two or three exceptions, of good quality. 
 The latter occur near the northwestern corner 
 of the valley, where there are some alkali spots 
 on a heavy, dark adobe soil, of which small 
 tracts are found on the western slope. 
 
 The aualyses of the red soil, taken to twelve 
 inches depth, and that of the subsoil, taken at 
 three feet depth, both on the Cajon Land Com- 
 pany's tract, resulted as follows: 
 
 Red Soil and Subsoil, Cajon Valley 
 
 Soil. Subsoil. 
 
 So. 791. No. 792. 
 
 Coarse Sand 20.00 25.5 
 
 Fine Earth 80.00 74.5 
 
 analysis of kink bartii. 
 
 Insoluble Matter 83.404 ) a _ „ nn 71.900 ) 9fl „.„ 
 
 Soluble Silica 3.S05 {*'- MJ 8.143 j" 30 -"* 3 
 
 Potash 729 .670 
 
 Soda .290 .188 
 
 Lime 775 1.028 
 
 Magnesia 692 1.340 
 
 Br. Oxide of Manganese. . .063 .054 
 
 Peroxide of Iron 4.358 7.392 
 
 Alumina 4.167 5.988 
 
 Phosphoric Acid 053 . 054 
 
 Sulphuric Acid 069 . 011 
 
 Water and organic Matter 1.913 3.081 
 
 7.450 
 
 Total 100. 31 S 
 
 Available Inorganic 334 
 
 Hygroscop. Moisture 2.312 
 
 Absorbed at 10° C. 
 
 The " coarse sand " shown in the above table 
 ranges from one-twentieth to one- fiftieth inch, 
 and consists mainly of various kinds of quartz, 
 with a little feldspar and some hornblende, evi- 
 dently of granitic origin. Most of the grains 
 are partly rounded, as though they had been 
 transported some distance. While the subsoil 
 I contains somewhat more of this saud or debris, 
 
 it also contains more clay than the surface soil, 
 as is plaiuly shown in its higher attraction for 
 moisture (7.5 instead of 2.3 per cent), and in its 
 stitfer working when wetted. Bjing deeply 
 covered by the light soil, this subsoil will be 
 slow to lose its moisture in the dry season, and. 
 being readily reached and penetrated by the 
 roots, the remarkable foot that these lands can, 
 to a great extent, be cultivated without irriga- 
 tion, finds its explanation. 
 
 Chemically, the difference between soil and 
 subsoil i3 but slight, so far as the supply of plant 
 food is concerned. In potash they are nearly 
 alike, and the supply ample; the phosphoric 
 acid percentage is identical, and quite low, yet, 
 in presence of a good supply of lime, especially 
 in the subsoil, which is of such unusual depth, 
 a deficiency in this respect will not be felt for 
 some time to come by deep-rooted crops. Phos- 
 phates will doubtless, however, be the first fer- 
 tilizers needing to be supplied when the time 
 comes. As in nearly all upland soils of the 
 southe. n region, the supply of vegetable matter 
 is quite, small, and should in cultivation be in- 
 creased by every possible means. 
 
 All the characters of this soil point to its 
 pre-eminent adaptation to the cultivation of 
 fruits, especially of those which, like the grape, 
 can readily be so managed as to draw but lightly 
 upon the phosphates and nitrogen of the soil, 
 by a return of the pommace and othor offal. 
 High quality rather than exuberant quanity of 
 product is foreshadowed by the soil char- 
 acters; yet the experience had shows that even 
 in the latter respect, the Cajon lands are not 
 behind, -the great thriftiness of vine and tree 
 growth being a matter of record; as is, also, 
 the excellent quality of both raisins and wine 
 already produced. Regarding the latter, the 
 analysis of a Zinfandel claret has been given 
 and commented on in a previous bulletin (No. 9). 
 
 The soil of the San IHego river valley is a 
 fine sandy loam of a dark mouse color, glisten- 
 ing with mica scales; it becomes somewhat 
 heavier downwards, and at three feet is choco- 
 late-colored and moderately coherent. From its 
 appearance it should be very productive. 
 
 E. W. Hilgaed. 
 
 Berkeley, Aug. 30, 1884. 
 
 /^V OF THE; A 
 
 UN1VER91TV J