STATE AGRICULTURAL SOCIETY. 209 



I would add but one suggestion, and that is that the decayed vege- 

 tation, trees, limbs, and underbrush of the timber lands, in both 

 ranges of mountains, are hardly given due prominence in the con- 

 stituency of the soil. 



Mr. Hilgard says: 



Broadly speaking, it may be said that in the northern division of the Sacramento Valley the 

 Sbils are prevalently loams, more or less heavy, largely interspersed with tracts of heavy clay 

 or "adobe" soils, often the exact counterpart of the " prairie" soils of the Mississippi Valley ; 

 while in the southern portion, or San Joaquin Valley, the bulk of the soil is altogether preva- 

 lently sandy, occasionally to the extent of rendering them sterile; and what is there called 

 "adobe," by way of contrast, would mostly be elsewhere considered a moderately clayey loam. 

 As to intrin'sic fertility, it would be ditficult to decide between the two divisions; for wliile the 

 heavier soils, other things being equal, are usually the richer in plant food, and tlierefore the 

 more durable, the great depth of the light soils of the San Joaquin Valley seems to compensate 

 in a measure for the somewhat inferior percentage of the plant food. This is the more true, as 

 the "sand" is to a considerable extent not simply siliceous, but consists largely of comminuted 

 granitic and eruptive rocks, with an admixture of the ancient slates, or rather schists, which 

 cover the flanks of the Sierra and constitute the proverbial " bed-rock." Moreover, the " foot- 

 hills" are commonly bordered, on the valley side, by a rolling plateau land, underlaid by the 

 marly strata of the tertiary formation; and these, commingling with the materials brought 

 from the higher lands, form' naturally marled soils, whose thriftiness, when under irrigation, 

 contrasts strikingly with their barren aspect during all but the Winter and early Spring months, 

 so long as they remain in their natural condition. 



From Redding, at the head of the Sacramento Valley, to Bakersfield, at that of the San 

 Joaquin, the valley has along its eastern border a belt of upland varying in width from one to 

 twenty miles, and" from fifty to twenty feet above the natural drainage level, the soil of which 

 is a yellow or reddish loamof varying character, evidently formed by an intermixture of the 

 red soil of the foothills with the valley deposits. Much of this land, which is mostly too high 

 to be reached by the present irrigation canals, has a singular hillocky surface, known as " hog 

 wallows," doubtless the result of aqueous erosion in past periods. These "hog wallow" lands 

 differ essentially both in their character and origin from those similarly named in Texas and 

 other Gulf States (which are mostly heavy prairie soils), and even as far south as Merced 

 County produce excellent cereal crops, as well as fruits, without irrigation. 



On the western or Coast Range side of the valley, the soils are usually materially different. 

 The Coast Range consists in the main of gray tertiary and cretaceous materials, prevalently 

 clayey northward of San Francisco Bay, but growing Tuore and more sandy, on the whole, 

 in a southward direction. Hence, we find extensive tracts of very stiff " adobe " soils of very 

 variable degrees of fertility on the western side of the Sacramento Valley, and as far south as 

 the southern line of San Joaquin County, where the widely gaping cracks of the adobe, during 

 the dry season, attract the attention of even the casual passer-by. Southward the soils lying 

 at the foot of the Coast Range become increasingly sandy, as do the bordering hills, until in the 

 region opposite Tulare Lake it is reported to be a " sandy desert." This statement may require 

 to be taken with a considerable grain of allowance, since in the absence of any opportunity for 

 irrigation, and of any serious attempts at settlement thus far, the capabilities of this region can 

 hardly be said to have been fairly tested. 



Tiie soils of the western border of the Sacramento Valley are at many points materially and 

 most beneficially modified by the admixture of materials contributed by the tributary valleys 

 heading within the region of eruptive or volcanic rocks, whose southern portion has become 

 noted for the high quality of the vines produced in the valleys of Sonoma and Napa. These 

 soils are also originally red, as is still the case on the mountain-sides and higher benches of the 

 valleys; and while less suited to cerial culture, they seem to be preeminently adapted to the 

 perfecting of the higher qualities of fruits. 



The orchard products of Vacaville, widely known for their excellence, are grown on such 

 soils; and the fruit-growing region of Solano and Yolo Counties, the present center of the raisin 

 industry, is covered by the joint deposits of the Sacramento River and Putah Creek, the latter 

 one of the main drains of the volcanic region. 



Soils quite similar to these, both in origin and productive qualities, exist on the opposite side 

 of the valley, where the Tuolumne, Mokelumne, and Cosumnes Rivers traverses the volcanic 

 tufas that cover the gold-bearing gravels of Table Mountain. As regards their general chemi- 

 cal character, the soils of the entire valley (of which quite a number have been analyzed, partly 

 under the direction of the State Agricultural College, partly under those of the Census Office), 

 are throughout remarkable for a high percentage of lime, which rarely falls below four tenths 

 of one per cent, and most commonly ranges from one half to one and a quarter jter cent. This 

 circumstance explains, in a measure, the high thriftiness of these soils, allowing the rapid devel- 

 opment and generous fruiting which accompanies the minimum allowance of moisture, and 

 maintains the farmer's hopes that the success of a single season will suffice to wipe out the 

 financial failures of two or three dry seasons. A generous allowance of potash accompanies the 

 lime even in the very sandy soils of the Tulare Plains, mostly exceeding four tenths, and rang- 

 ing as high as one and a quarter per cent. The phosphates are on the whole low in the sandier 

 soils of the San Joaquin Valley, but high in the adobe soils of both divisions. 



27 M 



