GROUP OF HEAVY SOILS. 
25 
type occurs as terraces or benches usually rather narrow, but 
extending along the streams for considerable distances. The 
part adjoining the upland rises slowly and frequently grades 
into the Knox silt loam so gradually that the boundary line must 
be arbitrarily placed. As this type is found chiefly at the foot 
of higher lying slopes, which are often very steep, large quan¬ 
tities of water must pass over the terraces during heavy rains, 
and as a result deep ravines are frequently formed. The origi¬ 
nal timber growth consisted chiefly of oak, with some hickory 
and a few other species. Most of the timber has been removed. 
In the ravines there is now a second growth of sumac, hazel, 
and other brush. 
Origin .—The material composing the type is largely of allu¬ 
vial origin and was deposited during glacial periods when the 
melting ice sheets to the north greatly increased the volume 
of water flowing down these rivers. It is probable that the sur¬ 
face material, especially close to the foot of the bluffs, is partly 
colluvial, having been washed down the steep slopes from the 
Knox sit loam areas, which are always found at higher eleva¬ 
tions. 
Present agricultural development .—Practically all the type 
is put to some agricultural use, and most of it is cultivated 
regularly. The crops generally grown and the yields obtained 
are: Corn, 45 to 50 bushels; oats, 25 to 40 bushels; barley, 30 
to 35 bushels; and hay, 1% to 2 tons per acre. Potatoes are 
grown on the type to a small extent for home use, but seldom 
on a commercial scale. The usual rotation consists of corn 
followed by a small grain, either oats or barley, or sometimes 
by one year of each of these crops, and then by clover and tim¬ 
othy mixed, seeded with the grain, the field being cut for hay 
one or two years, before returning to corn. The stable manure 
is usually applied to the sod to be plowed under for the corn 
crops. The methods of cultivation, fertilization, and treatment 
are practically the same as those practiced on Knox silt loam. 
The soil is not difficult to cultivate, and where the areas are 
of sufficient size to form fields or the larger part of a farm, 
this terrace soil may be considered one of the most desirable 
types in the county. 
