130 SCIENCE AND SOIL 



gravels, formed by colluvial and alluvial wash from granitic rock, mingled 

 with some shale and sandstone. These soils are adapted to fruit, truck crops, 

 sweet potatoes, melons, and alfalfa, under favorable conditions of irrigation 

 and drainage. 



PACIFIC COAST 



The soils of the Pacific coast, including those of the coastal and interior 

 mountain ranges, foothills, and valleys, have been classified into a number 

 of series, varying in field characteristics, topography, origin and mode 

 of formation, and agricultural importance. They range from residual and 

 colluvial soils of the mountain sides, foot slopes, and foothills, to deep and 

 extensive river flood plains and delta sediments, and ancient and modern shore 

 and marine lacustrine deposits. While some of these series are confined to a 

 single coastal or interior mountain range or valley, others are of wider range 

 and extend over several different physiographic regions. The value of these 

 soils and their adaptation to crops is dependent largely upon the possibilities 

 of irrigation and upon local conditions of rainfall and temperature, all of 

 which are to great extent dependent upon topography. They range in agri- 

 cultural importance from those devoted only to extensive grain farming to 

 the most valuable and intensively cultivated lands devoted to citrus and decid- 

 uous fruits, vines, small fruits, and other special crops. 



Anderson series. Reddish gray or light red alluvial soils occupying prin- 

 cipal valley plains and the bottoms of intermittent streams. Generally gravelly. 

 The soils of this series, when not too gravelly, are adapted to the production of 

 peaches, pears, prunes, and small fruits, but are, in so far as mapped at present, 

 inextensive types of secondary agricultural importance. 



Fresno series. Light-colored soils with light gray, ashy subsoils, and 

 alkali -carbonate hardpan, derived from old alluvial wash. Where protected 

 from alkali accumulations, these soils have been very successfully used for 

 vineyards and raisin grapes, and are particularly adapted to almonds, peaches, 

 and apricots. 



Hanford series. Recent alluvium of flood or delta plains derived from a 

 variety of rocks. The light-textured soils are light in color, and the heavy tex- 

 tured soils are dark in color. The lighter members of the series are adapted 

 to the same class of fruits and raisin grapes as the Fresno series. The heavier 

 members of this series, however, are better adapted to alfalfa, sugar beets, 

 celery, asparagus, and other truck crops. 



Maricopa series. Loose, dark-colored soils derived from unassorted col- 

 luvial or partially assorted alluvial materials, generally derived from granitic 

 or volcanic rocks. There are two heavy members of this series upon which 

 alfalfa, grain, and sugar beets are important crops. The lighter members, when 

 occupying positions so that they can be irrigated, are adapted to citrus and 

 deciduous fruits ; also vines. 



Oxnard series. Dark-colored alluvial or colluvial soils derived from higher 

 lying areas of sandstones and shales. Members of this series are used to a very 



