126 SCIENCE AND SOIL 



Vergennes series. Light-colored soils, with gray or whitish subsoils, 

 derived from Champlain clay, or lighter deposits over these clays. This 

 series includes the best hay and apple soils of the Champlain Valley. A wide 

 variety of tillage crops is grown, but cultivation of the heavier members of the 

 series is very difficult. 



RESIDUAL SOILS OF THE WESTERN PRAIRIE REGION 



This region consists of the nonglacial part of the prairie plains bounded 

 on the north by the Missouri River, the southern limit of glaciers, and extending 

 southward through Texas to the Rio Grande. On the west it merges into the 

 Plateau region at very near the 2ooo-foot contour, and on the east is limited 

 by the Gulf Coastal Plain and the Ozark Plateau. Its surface is gently rolling, 

 with occasional low hills, and is cut by numerous stream channels. The 

 rocks are of Carboniferous age, and consist of sandstones, shales, and limestones 

 more or less interbedded. These rocks give rise to three series of soils, viz. 

 Oswego, Crawford, and Vernon, together with a number of miscellaneous soils. 

 In Kansas and Texas these soils are in some instances more or less modified 

 by the admixture of gravel and sand from Tertiary deposits brought down 

 from the higher areas farther west occupied by crystalline rocks. 



Crawford series. Brown soils with reddish subsoils, derived from lime- 

 stones. The soils of this series range from rough areas suited mainly for 

 pastures to fertile general farming, fruit growing, and trucking soils. 



Oswego series. Gray or brown soils, derived from sandstones and shales. 

 The lighter members of this series are adapted to corn, oats, potatoes, truck, 

 and fruit ; the heavier to these crops and wheat. 



Vernon series. Brown to red soils typical of the Permian formation. Soils of 

 this series show a wide adaptation according to texture. General farm crops, 

 including cotton, corn, wheat, Kafir corn, and sorghum are the leading prod- 

 ucts. Small fruit, peaches, and truck are grown to some extent and are 

 capable of marked extension. 



GREAT BASIN 



With the exception of one soil type recognized in the Laramie area, Wyoming, 

 the soils in this group, so far as mapped, are confined to the Great Interior 

 Basin region. They are derived from a great variety of rocks, and consist 

 of colluvial soil of the mountain slopes, deep lacustrine and shore deposits of 

 the Bonneville period, and of recent stream-valley sediments and river-delta 

 deposits. 



When not situated above or outside the limits of irrigation, or rendered 

 unfit for cultivation by accumulation of alkali or seepage waters, they are of 

 great agricultural importance, and are devoted mainly to the production 

 of grains, sugar beets, alfalfa, stone or other tree fruits, and vegetables. 



Bingham series. Porous dark or drab colluvial and alluvial soils under- 

 lain by gravel or rock, occupying lower mountain slopes. The lighter types 



