CALIFORNIA ALLUVIAL LOAMS 31 



in composition, those of the southern region being more calcareous, 

 and apparently richer in phosphoric acid; as the coast region consists 

 for the most part of low ranges with intervening valleys, the valleys 

 are, as a rule, small, though a few show considerable area. In such 

 a country the soil surface shows wide diversity with its smaller areas 

 than on the vast stretches of the great interior valley; consequently, 

 so far as soil goes, the coast farms are often suited to a wider range of 

 fruits than the interior valley farms of similar size. 



ALLUVIAL OR SEDIMENTARY LOAMS 



These soils have been considered from the earliest plantings by 

 Americans as par excellence the fruit soils of the great valley of central 

 and northern California. They occur along the courses of existing 

 streams, and extend back to variable distances, until they merge into 

 the valley loams, or adobes. These deposits are considerably higher 

 than the present beds of the streams, and are sometimes described 

 as "next to river bottom." They consist of fine alluvium, with seldom 

 any admixture of coarse materials. These river soils are usually very 

 deep and they are naturally well drained. 



These deposits cross the valley in somewhat irregular courses ; they 

 are of greater or less width according to the drainage area whence 

 they have come. They vary also in depth, and taper down on either 

 side to the level of the red loam or adobe upon which they have been 

 deposited. Such strips are first chosen by the fruit planters of the 

 district in. which they occur. In the valleys of the rivers crossing the 

 eastern side of the San Joaquin Valley, there are, bordering the streams 

 as well as Tulare Lake, considerable areas of brown to blackish loam 

 varying from heavy to light, but for the most part easily tilled and 

 exceedingly rich. Considerable fruit has been grown for years on 

 these situations, and some kinds do well on these bottoms which do not 

 show adaptation to the plains. Some even of the higher lying portions 

 of these "black lands" support thrifty orchards without irrigation. 

 The wider stretches of alluvial soils in the upper part of the valley, as 

 in the Mussel Slough country and the Visalia region, for instance, are 

 notably well adapted to fruit growing. The occasional intrusion of 

 alkali, which must be carelly avoided, is the chief obstacle to the 

 general approval of these alluvial lands for fruit purposes. 



Soil of similar character is found in some small valleys consisting 

 of an alluvial wash from the bordering hills which in some places 

 reaches a depth of thirty feet or more without notable change in char- 

 acter. Such soils have proved very fertile and durable. 



The rich river bottom, adjacent to the beds of the main rivers and 

 sloughs of the valley, has usually a dark, rich, and moist soil, easily 

 tilled and not subject to baking and cracking. It is largely used for the 

 growth of vegetables and alfalfa, but considerable areas have been 

 planted with fruit trees, especially with pears, which do not suffer from 

 submergence of their roots for considerable time. 



In the coast valleys of the State there are also very extensive areas 

 of alluvial soils which are largely used in fruit production, as well 



