120 SCIENCE AND SOIL 



Sassafras series. Yellowish brown surface soils with reddish yellow to 

 light orange subsoils overlying gravel beds. 



Susquehanna series. Gray soils with heavy red clay subsoils which become 

 mottled and variegated in color in the deep subsoil. Only one member of 

 this series, the sandy loam, has been developed to any considerable extent. 

 This one is used for fruit and general farm purposes, but the other members 

 are particularly refractory and difficult to bring into a productive state. 



Webb series. Brown to reddish brown soils with reddish brown to red sub 

 soils, a semiarid prototype of the Orangeburg series. The soils of this series 

 have not been used to any great extent, owing to lack of irrigation facilities. 



Wickham series. Reddish or reddish brown terrace soils overlying reddish, 

 micaceous heavy sandy loam or loam subsoils. The soils of this series have a 

 relatively high productivity for general farm crops. 



Wilson series. Dark gray prairie soils with mottled gray subsoils. The 

 clay member of this series is a strong soil devoted to general farming, with cotton 

 as the leading crop. The other members are used for cotton, but are inclined 

 to be droughty. 



RIVER FLOOD PLAINS 



An extensive and characteristic group of soils, usually known as " bottom 

 lands," is found in the flood plains of numerous rivers and streams of the 

 United States. The largest development of this group occurs along the Mis- 

 sissippi River, where the bottoms are often many miles in width. 



The soils have been formed by deposition from stream waters during 

 periods of overflow. The texture of the material depends upon the velocity of 

 the current at the time of the deposition. Where the current is very rapid, 

 large stones and bowlders are borne along, and beds of gravel and sand are 

 formed. Along the swift-flowing streams the texture of the soil changes often 

 within short distances, but in wide bottoms large areas of very uniform soils are 

 often formed. The soil material has usually been derived from various kinds 

 of rocks, but in some instances is closely related to the surrounding geological 

 formation. The red soils along the Red and other rivers in the Southwest 

 have been formed by the reworking of the Permian Red Beds. In general, 

 the soils along the streams which flow through the prairie region have a darker 

 color than those along the streams which run only through the timbered sec- 

 tions of the country. 



The difference in the origin, drainage, color, and organic-matter content has 

 given rise to several series of alluvial soils in the humid portion of the United 

 States. 



Congaree series. Brown or reddish brown soils found along Piedmont 

 streams and representing wash from Cecil soils. Valuable and dependable 

 corn soils, but too low and moist for cotton. 



Huntington series. Dark brown to yellowish brown soils occurring along 

 streams in the Alleghany plateaus. Both the general farm crops and truck 

 crops thrive on these soils. 



