STATE AGRICULTURAL SOCIETY. 



189 



under good cultivation and with sufficient moisture. As they are 

 somewhat open they require deep tillage to enable the roots to pene- 

 trate readily through the gravelly subsoil, which, however, seems 

 quite loose and pervious. In view of the climate and the inadequacy 

 of water for irrigation, vine and fruit culture, but especially that of 

 the olive, seems indicated as their most profitable use. 



Soil and subsoil from Pomona Colony, Los Angeles County. Collected 

 by Mr. N. J. Willson from Mr. House's place, three-quarters of a mile 

 north ten degrees west from Pomona railroad station. The soil 

 and subsoil scarcely difi'er in appearance down to thirty-two inches 

 depth, and constitute a reddish-gray, rather sandy loam, easily tilled. 

 Natural vegetation, alfilerilla, clover, malva, and rattleweed (Astra- 

 galus Sp.); produces about twenty-five bushels of wheat and ten tons 



of ' ■ ■ ■ 



cer( 



that of twelve to thirty-two inches. 



alfalfa per acre when irrigated, and is well adapted to fruits and 

 reals. The soil was taken to the depth of twelve, the subsoil from 



Soil and Subsoil from Pomona. 



This soil, judging from the great similarity of appearance, may be 

 taken as representing a large area of similar lands in the San Bernar- 

 dino Valley. The soil and subsoil differ but very slightly in com- 

 position. Both have a large supply of potash and lime, as well as 

 magnesia, and in both the phosphoric acid is low; in tlie soil quite 

 deficient, but apparently increasing with the depth. _ The supply of 

 humus is very small, and its increase by green manuring would seem 

 to be among the first needs suggested by the analysis. It must not be 

 forgotten, however, that in these dry regions the surface soil is often 

 of less importance than the subsoil, within which the roots must 

 remain in order to be secure from heat and drought. Evidently such 

 soil, while at first capable of high yields, will soon need phosphate 

 fertilizers for the continued production of shallow-rooted crops at 

 least; while alfalfa, vines, and other deep-rooted plants, will be able 

 to draw upon the deep subsoil for their supply of that ingredient for 

 a long time to come. 



