48 
SOIL SURVEY OF BUFFALO COUNTY. 
More than half the area of the Plainfield sand is under culti¬ 
vation, although as a whole it must be considered of rather low 
agricultural value. During the most favorable years, when the 
rainfall is well distributed, fair crops are obtained, but usually, 
owing to the lack of moisture and of plant food, the ordinary 
yields are not satisfactory. That part of the type immediately 
along the bluffs has probably been influenced to some extent by 
the wash from the heavier upland soils, and for a short distance 
from the bluffs yields are usually better than along the outer 
margin of the type. Some areas are uncultivated practically all 
of the time, because of their extremely sandy nature and con¬ 
sequent low productiveness. On some fields a crop is grown 
every second year and the ground fallowed in alternate years. 
On this type rye is an important crop and yields of 20 to 25 
bushels per acre are common during the most favorable years. 
Corn yields 25 to 40 bushels per acre under the most favorable 
conditions, but the ordinary yields are far below these figures. 
Buckwheat is grown to some extent. Clover can be grown suc¬ 
cessfully only on the lower, darker portions of the type, and 
even here the yields are not large. Potatoes do fairly well, but 
only a few are grown for market. 
The selling price of land of this type ranges from $10 to $40 
an acre, depending upon location, improvements, etc. 
CHEMICAL COMPOSITION AND MANAGEMENT OF SANDS AND FINE 
SANDS. 
On chemical composition these sandy soils show much less of 
the important plant food elements than do the upland silt loam 
soils of this county. The total phosphorus in the surface 8 inches 
averages 700 to 800 pounds per acre, while the amount of po¬ 
tassium is about 16,000 pounds in an acre inches. The organic 
matter in these soils is about half that in the Knox silt loam 
and less than one third of that in the dark prairie soils of the 
state. 
Since Potsdam sandstone is the chief source of essentially all 
of these soils, they are low in lime carbonate, except in a few 
places where the sand occurs at a lower level than the beds of 
limestone, and thus receives a small amount of lime carbonate in 
the water from the higher slopes. The surface soil of all these 
types is acid, and will require lime. While these soils are defi- 
