96 PRINCIPLES OF AGRICULTURAL CHEMISTRY 



chemical properties. Finally, the types, or individual soils, are 

 based on texture and structure. This scheme offers good possi- 

 bilities; the group, acid and basic igneous rocks, is, however, a 

 broad one and should be sub-divided. 



Some Soil Series. Soil types numbering 715 have been 

 established by the Bureau of Soils of the United States Department 

 of Agriculture. These types have been divided into 86 series. 

 A full list and description of these types and series is found in 

 Bulletins 55 and 78 of the Bureau mentioned. The following are 

 a few series, mentioned for the sake of illustration. 



Atlantic and Gulf Coastal Plains. Houston Series. Dark-gray 

 or black calcareous prairies. One of the most productive series 

 for upland cotton, and well adapted to alfalfa and other forage 

 crops. 



Norfolk Series. Light-colored soils with yellow sand or sandy 

 clay subsoils. This series contains some of the most valuable 

 truck soils of the Atlantic and Gulf Coast States, and certain 

 members of the series are adapted under certain climatic condi- 

 tions to wheat, grass, tobacco, and fruit. 



Orangeburg Series. Light-colored soils with red sandy clay 

 subsoils. This series constitutes some of the best cotton soils of 

 the South, and certain members of the series are particularly 

 adapted to tobacco. 



Portsmouth Series. Dark-colored soils with yellow or mottled 

 gray sand or sandy clay subsoils. Where drainage is adequate, 

 this series is adapted to some of the heavier crops, to small fruits, 

 and to Indian corn. 



Susquehanna Series. Gray soils with heavy red clay subsoils 

 which become mottled and variegated in color in the deep subsoil. 

 Only one member of the 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 particu- 

 larly refractory and difficult to bring into a productive state. 



River Flood Plain. Miller Series. Brown to red alluvial soils 

 formed from the reworking of materials derived from the 

 Permian Red Beds. Very productive soils, suitable for cotton, 



