110 SOIL PHYSICS AND MANAGEMENT 



production of citrous and stone fruits, figs, grapes, small fruits, 

 and truck crops. 



Stockton Series. The lighter members of this series have a 

 buff to reddish or chocolate brown color. The heavier members 

 generally exhibit a marked adobe structure, are usually free from 

 gravel, and range from dark brown to dark gray or black in color. 

 The heavier members are devoted mainly to the production of 

 grains and hay. 



Redding Series. The soils range from reddish gray to deep 

 red, are usually gravelly and sometimes carry large amounts of 

 alkali and partially indurated clay-iron hardpan. Strawberries 

 and bramble fruits yield abundantly. 



Whatcom Series. The soils of the Whatcom series are of a 

 deep reddish brown color and prevailingly of fine texture and rather 

 compact structure. The surface soil is often dark brown or nearly 

 black. Subsoils consist of drab to gray plastic and compact heavy 

 silts, the upper portion carrying some gravel and glacial boulders. 

 Soils are derived from compact glacial drift and occupy areas of 

 undulating to rolling upland. The soils are adapted to small and 

 orchard fruits, potatoes, vegetables and hay crops. 



Willows Series. The soils range in color from brown to red- 

 dish brown or dark chocolate brown and are free from gravel. 

 The subsoils are light brown to reddish brown or sometimes yel- 

 lowish and mottled with gray. They have a compact, relatively 

 impervious structure and often contain lime and gypsum-. They 

 are derived mainly from calcareous shales, sandstone, and shaly 

 sandstone rocks. Where well drained and free from alkali, they are 

 well adapted to the production of alfalfa, grains and, with the ex- 

 ception of those areas of extremely heavy texture, sugar beets. 



Yolo Series. This series embraces alluvial soils of brown or 

 dark brown color, underlain by lighter brown subsoils. The types 

 have been derived from schists and other metamorphic rocks, with 

 some material from shaly sandstones and shales. Where capable 

 of irrigation, fruits, vegetables, and forage crops can be grown. 



(b) River Flood Plains Chehalis Series. The soils are of 

 recent alluvial origin, occupying stream valleys, traversing the 

 region of residual basaltic soils that vary from gray or drab to 

 reddish brown, some of the heavier types containing very much 

 organic matter and showing a dark brown to black color. The sub- 

 soils vary from yellow, gray or mottled to light brown, dark brown, 



