THE MIAMI SEMES OF SOILS. 41 
Although the deeper subsoil of all parts of the type is usually well 
supplied with limestone, it has been found that the surface soil is de- 
cidedly benefited by the application of ground limestone at the rate 
of 1 ton or more per acre. The limestone is helpful in securing better 
stands of clover and decidedly essential to the growing of alfalfa. 
Hay, oats, and corn constitute the crops most extensively grown, 
while winter wheat and barley are also important. In the more 
southern areas hay and grain production and the fattening of beef 
cattle are the dominant industries, while in Wisconsin the growing of 
general farm crops and dairying predominate. 
THE MIAMI CLAY LOAM. 
The Miami clay loam is most extensively developed in Indiana, 
Michigan, and Ohio, though small areas are found in Wisconsin and 
Iowa. A total of 2,342,410 acres of this type has been mapped in 
the five States in which it has been encountered. The soil surveys 
already completed, however, indicate that the Miami clay loam con- 
stitutes one of the dominant soils of central and western Ohio, north- 
ern Indiana, and southern Michigan. From all of the localities in 
which this type has been recognized its area extends into bordering 
counties, indicating the existence of millions of acres of the type 
within the general region in which the Miami series is developed. 1 
The surface soil of the Miami clay loam is a brown, yellow, or gray 
silty loam. The depth of this surface soil is rarely less than 6 inches, 
except in small areas on steep slopes, where erosion has been active. 
It is generally more than 10 inches in depth, constituting an unusu- 
ally deep surface soil. This material is frequently underlain by a 
yellow or brown heavy silty loam which extends to a depth of about 
2 feet, and this in turn is underlain by a brown, yellow, gray, or drab, 
frequently mottled silty clay loam or heavy clay. At a depth vary- 
ing from 2 feet to 5 or 6 feet the typical blue or drab bowlder clay, 
with the characteristic glacial pebbles and bowlders, is almost uni- 
versally developed. Only on slopes and in other localities where the 
surface soil and subsoil are unusually shallow is the consolidated 
underlying rock encountered. Usually the depth of the glacial till 
over bedrock is from 40 to 250 feet. The Miami clay loam is de- 
rived from deep, complex, mechanically broken soil-making material 
of glacial origin. The soil itself has been slowly formed through the 
processes of weathering of the surface portion of this material. The 
glacial origin of the soil, insuring the commingling of earthy mate- 
rial from a great variety of sources, the great depth of the soil-mak- 
ing material, and the compact nature of the mass which resists exces- 
1 It is probable that some areas of Miami silt loam have been included with areas of the 
Miami clay loam in some of the earlier soil snrveys In Ohio and Indiana. 
