UNIVERSITY OF CALIFORNIA. 
 
 AemCULTURAL EXPERIUENT STATION. 
 
 BULIiETlN NO. 44. 
 
 The "Bedrock Lands" of Sacramento 
 County. 
 
 The high quality of the fruit produced in the 
 foothill lands of the Sierra is well recognized, 
 and as time progresses a large proportion of 
 these lands will undoubtedly be given to or- 
 chards and vineyards. The border lands of the 
 great valley lying along their foot, that have thus 
 far been mostly devoted to wheat-growing, are 
 likely to share the same fate, provided the ex- 
 pansion of the market for California fruits, 
 now forming the subject of much anxiety and | 
 discussion, shall justify a corresponding en- 
 largement of the area of fruit culture. The 
 soil of these border lands varies from a grayish 
 loam of alluvial character, occupying the lower 
 ground, to a yellow or reddish soil which 
 usually forms low broad ridges running from 
 the foothills proper into the valley; the inten- 
 sity of the tint increasing as the hills are ap- 
 proached, where the prevailing color is the 
 proverbial *'red" of the placer mines. 
 
 On the foothills from Butte south to Amador 
 the adaptation of the soil to fruit and vine cul- 
 ture seems to be little more than a question of 
 depth above the bedrock ; although in numerous 
 cases the latter is itself so soft that the roots 
 of the hardier kinds, such as the vine, fig, 
 olive and carob, can without difficulty make 
 their way into, and draw both moisture and 
 sustenance from it. In the rolling border lands 
 of the valley the soil, or rather subsoil, is 
 usually of sufficient depth and penetrability for 
 all purposes; but to this rule there are excep- 
 tions, in the local occurrence of tracts ranging 
 from a few acres upwards, where an apparently 
 impenetrable material underlies at depths vary- 
 ing from one to several feet; and although this 
 material is altogether dififerent from the slates 
 underlying the foothill lands, the fact that it 
 produces the same effect on the welfare of fruit 
 trees has caused the local name of **bedrock 
 lands" to be given to such tracts. 
 
 An able article, giving an account of the 
 region in question, appeared in the Sacramento 
 Bee in May last, and a few weeks afterwards a 
 set of representative samples of soil, subsoil and 
 "bedrock" with underlying strata, carefully 
 taken according to directions, was furnished by 
 Mr. Wm. A. Lawson, of the staff of the Bee, 
 with the inquirv whether the lower layers 
 
 would, if broken, contribute anything to the 
 nutrition of trees. These samples were from 
 the neighborhood of Florin, Sacramento county, 
 from which region a sample of surface soil had 
 been previously sent by Mr. James Rutter, of 
 Florin. About a month later, a corresponding 
 set of samples were received from Mr. D. 
 Lubin, of Sacramento, showing the state of 
 things on some portions of Weinstock & Lubin 's 
 ranch near Mayhew Station, on the Sacramento 
 Valley Railroad. Although derived from local- 
 ities several miles apart, the two sets agree 
 very closely, and show the following arrange- 
 ment of layers: 
 
 1. Pale orange surface loam, four to forty- 
 eight inches thick. 
 
 2. Stiff brownish abobe, three to twelve 
 inches thick. 
 
 3. Brown or whitish hardpan, one to ten 
 feet thick. 
 
 4. Brown or white coarse sand, depth not 
 known. 
 
 No. 1, the loam forming the soil and ordin- 
 arily the subsoil of the region is apparently 
 identical in the two localities, and is scarcely 
 distinguishable from the soils prevailing, e. g., 
 near Wheatland, Yuba county, in a correspond- 
 ing position; it also agrees very nearly in the 
 essentials of shemical composition. 
 
 The brown adobe. No. 2, which forms an al- 
 most uniform layer over the bedrock every- 
 where, has evidently been formed out of the 
 latter in the course of time by the usual process 
 of soil-formation and, as will be seen below, 
 the two scarcely differ in compoBition more 
 than might different portions of either, from 
 each other. 
 
 The ^'bedrock" hardpan. No. 3, differs some- 
 what in aspect in the two localities. At May- 
 hew Station it is a yellowish-white, almost 
 chalky, uniform mass, covered on top by a 
 blackish, smooth, almost shiny crust an eighth 
 of an inch thick, manifestly formed by the depo- 
 sition of brown irco }re (limouite); it would, 
 alone, effectually p ;;vent the penetration of 
 roots into the ht-tcf ^n. The latter is quite 
 compact and free from grit above, but down- 
 ward gradually becomes more friable and sandy, 
 and finally seems to pass into almost pure, 
 sharp sand, at times of a strong rusty tint, but 
 mostly white. Mr. Lubin states that this rock 
 crumbles on exposure to the air. 
 
 At Florin the "bedrock" is less compact, of a 
 rusty tint, and instead of the hard, shining 
 crust on the surface, it is penetrated in all direc- 
 tions by blackish streaks of the iron ore. It 
 seems more nearly ready to form the adobe than 
 the material at Mayhew, and is more readily 
 penetrated by roots, but in general character is 
 very nearly alike. 
 
 These differences account for some differences 
 in the experience had in this bedrock land in 
 
regard to the success of orchard trees planted 
 on it. It is stated that they flourish for a few 
 years, varyiag with the depth of the soil, but 
 about the time that the roots reach and would 
 need to penetrate the hardpan layer, they cease 
 growing and often finally die. The question 
 arises whether this is due simply to the impene- 
 trability of the **bedrock," which prevents the 
 roots from gaining access to a sufficient supply 
 of moisture and plant food; or whether any in- 
 jurious ingredients, or other conditions, play a 
 part in the failure of the trees. 
 
 The analysis of the samples from Florin of 
 the three successive layers — the surface loam,* 
 adobe and hardpan or "bedrock," gave the 
 following results: 
 
 Coarse material 
 
 Fin e earth 
 
 Chemical Analysis. 
 
 Insoluble matter 
 
 Soluble silica . . . 
 
 Potash 
 
 Soda 
 
 Lime ' 
 
 Magnesia 
 
 Br. oxide of manganese 
 
 Peroxide of iron 
 
 Alumina , , , 
 
 Phosphoric acid 
 
 Sulphuric acid 
 
 Water and organic matter. . 
 
 Humus . 
 
 No. 1. 
 Soil. 
 
 48 
 95.2 
 
 82.936 
 6.277 
 .278 
 .073 ' 
 .599 I 
 .226 I 
 .089 
 1.908 I 
 5.419 1 
 .019 
 .011 
 2.262 
 
 No. 2. 
 Adobe 
 Subsoil. 
 
 No. 8. 
 Bedrock. 
 Hardpan 
 
 72.071 
 7.507 
 .378 
 .163 
 .622 
 .640 
 .020 
 5.100 
 9.440 
 .045 
 .014 
 4.123 
 
 I 100.097 100.023 
 
 I .461 1 
 
 Available phosphoric acid, i .016 I 
 
 Hyofroscop. moisture [ 2.66 
 
 Absorbed at | 14° o. ' 
 
 7.655% 
 
 72.652 
 6.118 
 .427 
 .143 
 .614 
 .947 
 .019 
 5.645 
 9.311 
 .081 
 .011 
 4 083 
 
 100.051 
 
 8.738% 
 
 * Sample sent by Mr. Jas. Rutter. 
 
 It is curious to note in the above analyses, 
 that, notwithstanding the great difiFerences in 
 the appearance of the three materials, they do 
 not diflfer widely in most points of their compo- 
 sition. The prominent points of difference are 
 that the surface soil contains about 10 per cent 
 more of inert matter (fine sand) than the other 
 two, but much less iron, and only a very min- 
 ute amount of phosphoric acid. The latter, 
 however, increases very rapidly downward, the 
 adobe containing more than twice as much as 
 the top soil, and the "bedrock" again nearly 
 twice as much as the adobe, or four times as 
 much as the surface soil. The deficiency of the 
 phosphoric acid in the soil is measurably offset 
 /im • »t ( 016 out of 
 
 .019), IS in an available condition, and hence 
 the deficiency has not been much felt in the past; 
 yet It does seem quite important that the rela- 
 tively large supply in the lower depths should, 
 If possible, be rendered accessible to the roots 
 
 of trees. The supply of lime is nearly the 
 same in all, and probably adequate, although 
 more would be desirable in the stiff adobe, 
 
 It is certain that this desirable downward 
 penetration of tree roots is not possible, when, 
 as near May hew Station, they encounter a hard, 
 polished crust covering a very solid hardpan 
 of several feet depth; and while at Florin the 
 hard crust is less prominent and the material 
 less solid, yet its condition indicates a want of 
 drainage during the wet season, causing the 
 formation of iron solutions, injurious to the 
 root tips, exactly as in the other locality. It 
 is obvious that the roots cannot go far during, 
 the season through such a substratum ; and 
 the breaking up of the latter by some financially 
 practicable method would seem to be the neces- 
 sary condition for the success of orchards. 
 
 Messrs. Weinstock & Lubin have attempted 
 this on a somewhat extensive scale on their 
 ranch near Mayhew. Mr. Lubin describes the 
 process as follows: " A hole 5x6 feet and six 
 feet deep was dug for each tree. It is necessary 
 to blast the bedrock layer with giant powder ; 
 even when using from three to five sticks much 
 picking has to be done, in order to shatter 
 thoroughly the several sedimentary layers. The 
 work thus done is quite thorough but very cost- 
 ly, ranging from $65 to $75 per acre. Messrs. 
 Kroll and Rutter simply drill a hole with 
 auger, put in a charge of black powder which 
 blasts a little rock, and then plant their trees. 
 Query — Will this be sufficient in the long run? 
 It would cost only about $30 per acre, and 
 would be cheap at that if the land could thus 
 be made to grow Bartlett pears and the like." 
 
 It certainly seems very desirable to avoid the 
 heavy expense of digging through the ** bed- 
 rock ;" and if it can be sufficiently shattered by 
 blasting at the bottom of a bore-hole, all that is 
 really needful will have been accomplished. A 
 charge of common black powder is not likely to 
 do this; while on the other hand, so high an ex- 
 plosive as dynamite would not be sufficiently 
 extensive in its pulverizing action, as is shown 
 by the use of so many cartridges in one hole by 
 Mr. Lubin. I theretore suggested the use of 
 " Judson powder" in a bore hole of sufficient 
 depth, and the subsequent digging of the holes 
 to the usual depth only. 
 
 In a late communication Mr. Lubin states 
 that Judson powder does not do sufficient exe- 
 cucion in the "bedrock," and that giant pow- 
 der No. 2 seems preferable. The kind of ex- 
 plosive to be used with the greatest advantage 
 will naturally vary from place to place, with 
 the nature ot the hardpan, and will have to be 
 ascertained by trial— which cculd best be made 
 before the rains set in. But in view of the fact 
 that the substratum of the "bedrock lands" is 
 shown to be actually richer in plant food than 
 the surface soil; that while in its natural con- 
 dition it not only obstructs the passage of the 
 roots mechanically, but also iniures them by 
 
 I 
 
the formation of poisonous BolutionB in conse- 
 quence of the stagnation of water; all of which 
 can be relieved by the shattering of the sub- 
 stratum by means of judicious blasting, also giv- 
 ing the roots access to abundant moisture: It 
 would certainly seem that in favorable locations, 
 where land is valuable, this mode of rendering it 
 available for fruit culture deserves most earnest 
 consideration. Neither the adobe nor the *'bed- 
 rock" should be used in the filling up of holes 
 
 at er planting, any more than a raw subsoil 
 should be turned on the surface in other cases. 
 But with the access of air and water to the 
 shattered portion, the substrata will gradually 
 go through the processes of soil forraatiou; and 
 their plant food will doubtless become available 
 fast euough to insure the welfare and product- 
 iveness of an orchard for the usual period. 
 
 E. W. HiLGARD. 
 
 Berkeley, Oct. 2d, 1885,