2 ) BULLETIN U2, U. S. DEPARTMENT OE AGRICULTURE. 
feet is a brown or yellowish-brown silty clay loam, which is in most 
cases underlain by a heterogeneous mixture of sand, gravel, clay, and 
bowlders. Gravel and bowlders in varying quantities are also scat- 
tered over the surface and mixed with both soil and subsoil. In 
some cases the type occurs over small hills, and in such positions it is 
underlain at shallow depths by limestone. 
The topography varies considerably, although over most of the 
areas it is rolling to hilly. On the steeper slopes it is necessary to 
leave this type in grass or in forest in order to prevent erosion. 
These features are shown in Plate III, figure 2. The natural drain- 
age of the type is good, and in places where the gravel beds or the 
underlying rocks are near the surface it is excessive, causing the soil 
to be droughty in years of light rainfall. 
The Miami gravelly loam is derived from glacial till, or partially 
reworked glacial till occurring in the form of glacial moraines, 
kames, and eskers. In some places where the covering of glacial ma- 
terial is shallow the underlying rock has contributed limestone frag- 
ments, at least to the lower subsoil. 
The type was originally forested with a growth consisting chiefly 
of maple and oak, with some hickory. 
Where the soil and subsoil have a total depth of 24 inches or more 
and where the surface slopes are not too steep, fair average yields 
are produced during seasons of normal rainfall. Where the surface 
covering is less than 2 feet either over the gravel or the underlying 
limestone, crop yields are Ioav, and such areas are of greater value for 
grazing than for the production of cultivated crops. Corn, oats, 
barley, and mixed hay are the chief crops on the tilled areas. The 
rougher areas are utilized chiefly for permanent pasture and farm 
woodlots. Not over one-half of the type is used for crop production. 
MIAMI GRAVELLY SAXDY LOAM. 
The Miami gravelly sandy loam has a total area of 66,944 acres 
xti Jefferson and Waukesha Counties, Wis. 
The surface soil of this type, extending to a depth of 8 to 10 
inches, consists of a light-brown sandy loam. Where typically de- 
veloped the soil is friable and rather loose. Varying quantities of 
gravel and numerous bowlders are found in the surface soil. The 
larger bowlders are usually removed from cultivated areas. The 
subsoil to a depth of about 2 feet is a reddish-brown or yellowish- 
brown gritty clay loam. This is generally underlain by a mass of 
gravel, cobblestones, and bowlders. The stony material largely con- 
sists of limestone. 
The topography of the Miami gravelly sandy loam ranges from 
rolling to ridged and hilly. The material is derived chiefly from 
