GROUP OF POORLY DRAINED SOILS. 
61 
which contains a large amount of organic matter. In numerous 
places there is a thin layer of peat or muck over the surface of 
the earthy matter. This organic matter layer, however, is not 
sufficient to justify classing the type as peat or Muck. The sub¬ 
soil consists of a black or darkf brown heavy loam or silty clay 
loam which at from 18 to 24 inches usually becomes gray or 
bluish in color, with numerous yellow and rusty mottlings. In 
the lower portion of the 3 foot section the texture frequently 
becomes lighter and is often a fine or very fine sandy loam. 
The type is subject to considerable variation in texture, depth 
of the black soil over the bluish subsoil, and also in the sand 
layer in the deep subsoil. It is uniform however in being all 
rather heavy, dark colored, high in organic matter and all 
poorly drained, giving it all a uniformity in its present agri¬ 
cultural value. 
Topography and drainage. —The surface of this type is level, 
or having only a very gentle slope toward the stream along 
which it occurs. The small depressed tracts frequently have a 
saucer shape. Because of its low position, and its situation 
adjacent to streams its natural drainage is very deficient. Prac¬ 
tically all of that along streams is subject to overflow, and much 
of it is under water for some portion of each year. 
Origin. —The portion of the type adjacent to streams is 
largely of alluvial origin with a large accumulation of organic 
matter in surface. The parent material came largely from the 
crystalline rock region, although within the area much of the 
soil lies directly over sandstone formations. The part of the 
type which is not adjacent to streams is largely of glacial origin 
and occurs chiefly in shallow potholes or slight depressions where 
drainage is deficient, and where there has been an accumulation 
of organic matter. In most cases there is no lime carbonate in 
the material forming this soil and the material shows varying 
degrees of acidity. 
Native vegetation. —-The native vegetation on this soil consists 
of willows, elm, ash, soft maple, and some poplar. There are 
quite extensive tracts which are treeless, and where there is now 
only a dense growth of coarse marsh grass. 
Present agricultural development. —The chief use made of this 
soil is for pasture and hay, but a considerable part of it is too 
wet even for such use. 
Chemical composition and fertility. —The Whitman silt loam 
is quite similar to the Clyde silt loam of southeastern Wisconsin, 
