THE MIAMI SEEIES OF SOILS. 17 



in mapping the soils, some of them are included with areas of the 

 Miami types. In other cases the surface covering of this dark-col- 

 ored soil is too shallow to warrant the separation of such areas, and 

 there are included within the limits of certain types of the Miami 

 series small areas in which the surface soils are considerably darker 

 than the average of the series. Such areas are in rather sharp con- 

 trast with the prevailing light-colored Miami surface soils, but are 

 necessarily included with the more typical development. 



The details of surface topography and drainage, of local variations 

 in derivation and thickness of the soil-forming material, of degree 

 of agricultural development, and of cropping systems can only be 

 given in the detailed soil surveys of counties and other areas. From 

 such surveys and from the examination of areas not yet covered by 

 the soil survey the main characteristics of the different soils of the 

 series are summarized. 



TYPE DESCRIPTIONS. 



MIAMI SAND. 



The Miami sand is mapped in Waukesha County, Wis., over a 

 total area of 1,920 acres. This type consists of a yellowish to brown- 

 ish gray medium to fine sand 6 to 8 inches deep, underlain by a yel- 

 low, loose, incoherent sand of the same grade. The soil is very low in 

 organic matter. Because of its loose, open structure it is easily cul- 

 tivated, and can be worked under almost any moisture condition. 

 Where the surface is not covered by a crop the sand is sometimes 

 drifted by the wind, though not to any great extent. 



Owing to the gently rolling to rolling topography, together with 

 the loose, open character of the soil and subsoil, the drainage is ex- 

 cessive, and crops suffer from drought, except during seasons of 

 unusually well distributed rainfall. 



Practically all of the Miami sand is derived from glacial moraine 

 material. The type was originally forested with a scrubby growth 

 of bur oak, red oak, and white oak. At present hazel bushes cover a 

 part of the type. The greater part of it is under cultivation, the 

 principal crops being corn, oats, rye, and clover. When the rainfall 

 is well distributed, fair yields are obtained. The land is not highly 

 developed. 



Soils like the Miami sand are better adapted to early truck crops 

 than to general farming. For any crop it is necessary to increase 

 the organic-matter content of the soil. This is best accomplished 

 by frequently turning under green manuring crops and saving and 

 applying all available stable manure. 



55813°— Bull. 142—14 3 



