20 BULLETIN 141, U. S. DEPARTMENT OF AGRICULTURE. 
in the different areas from a gray or white sand to a gray silty clay. 
In almost all cases the surface soil is immediately underlain by a 
layer of gray or white sand of medium to coarse texture to a depth 
of 2 or 3 feet from the ground surface. This is, in turn, underlain 
by a heavier and more silty or claylike deep subsoil which is. very 
retentive of moisture. 
Not infrequently a small amount of fine gravel is found, inter- 
mingled with both the surface soil and subsoil. It does not usually 
interfere with the cultivation of the soil and is not so abundant nor 
so generally present as to make any appreciable difference in the 
relationships of the soil type # to moisture. 
The Clyde sand is always found in level tracts which are de- 
pressed below the general level of the surrounding uplands and in 
positions where either glacial outwash or later soil wash from sandy 
upland areas has accumulated under conditions of poor drainage. 
There are no elevations or irregularities of surface which would 
interfere with cultivation. Frequently the areas occupied by the 
Clyde sand still receive wash from higher lands, and they also re- 
ceive a considerable amount of seepage water from adjacent porous 
soils of greater elevation. 
Practically all areas of the Clyde sand are found to be in a swampy 
condition when first occupied, and many areas have remained unre- 
claimed by artificial drainage, As a result of this condition large 
amounts of vegetable matter in a partly decayed state have accumu- 
lated in the surface soil, rendering it black in color and loamy in 
texture. Similarly the drab or gray color of the subsoil is an indi- 
cation of poor natural drainage. The excess water held in the subsoil 
has excluded the air, and there has been little or no weathering and 
oxidation of the iron-bearing minerals of the subsoil. Wliere drain- 
age has been partly established the subsoil colors are tinged with 
yellow or brown. 
Wherever the Clyde sand has been occupied for the more intensive 
forms of agriculture it has been necessary to establish open ditches 
for the outlets of extensive tile underdrains or in connection with 
smaller open farm ditches. In its natural condition the Clyde sand 
supports a thick growth of water-loving trees and of swamp grasses. 
In such localities its chief economic use is as pasture. Only when 
artificial drainage has been installed is the type well suited to crop 
production. 
Where the Clyde sand has been properly drained it has been suc- 
cessfully occupied for the production of the general farm crops, of 
which the yields are moderate. Corn is one of the most extensively 
grown and important crops. The large amount of organic matter 
in the surface soil, the ease with which a good moisture supply is 
maintained, and the easy tillage of this soil tend to make it one of 
