40 BULLETIN 141, U. S. DEPARTMENT OF AGRICULTURE. 
sloping topography. In practically all cases these different areas 
represent either lakes and ponds or extensive swamps which existed 
before artificial drainage was supplied. In its natural condition the 
Clyde silty clay loam supported a heavy growth of deciduous water- 
loving trees, including several varieties of oak and ash, elm, and silver 
maple. Treeless areas were covered with a rank growth of 'sedges 
and swamp grasses. In the early settlement of the country these 
swampy areas were left undrained, and it is only within more recent 
times that large areas of the Clyde silty clay loam have been re- 
deemed for agricultural uses through the installation of expensive 
open drainage ditches and the laying of tile underdrains. In some 
of the smaller areas the cutting of a single drainage ditch has fre- 
quently been adequate to drain the type, while larger areas have been 
brought under cultivation through the extensive community ditches 
into which individual farms and fields have been drained by means 
of tile. At the present time nearly all of the larger areas and many 
of the smaller tracts have been thus improved, and probably 75 per 
cent of the total area of the type is now used for the production of 
some crop. 
The Clyde silty clay loam consists of poorty drained areas in the 
glacial till upland, of swampy tracts along some of the smaller 
streams, and of areas of previously swampy land in the basins of 
extinct glacial lakes. The surface material to a depth of 2 feet or 
more usually consists of a mingling of silty material washed in from 
the surrounding uplands and of a large amount of partially decayed 
organic matter contributed by the marsh vegetation which flourished 
under previous conditions. 
The Clyde silty clay loam requires rather careful management to 
secure the best crop results. If it is plowed and harrowed when 
either too moist or too dry it is liable to become baked or clodded, 
with a corresponding decrease in crop production. When it is 
plowed in the proper condition of moisture the surface soil crumbles 
into a granular loamy mass capable of producing excellent crops. It 
is upon thoroughly drained areas that the best results are obtained, 
and drainage is the most fundamental form of improvement for this 
type. 
In practically all of the areas where the Clyde silty clay loam has 
been adequately drained corn constitutes the chief crop. It is usually 
planted for two or more years in succession before being followed by 
a small grain crop. In some instances it has been grown for 10 or 
15 years without serious diminution in yield. Corn produces from 
40 to 80 bushels per acre, with a general average in excess of 45 
bushels per acre. Both the yellow and white dent varieties are 
grown. A considerable acreage of corn is grown for cutting into the 
silo, giving yields of 12 to 15 tons per acre. This use of the corn 
