24 BULLETIN 13<M, U. S. DEPARTMENT OP AGRICULTURE 
CROPS ON PRAIRIE SOD 
Statistics published by the Colorado State Board of Immigration 4 
show that less than one-third of the land of northeastern Colorado 
is now under cultivation. This indicates that there is still consid- 
erable acreage under sod that is suitable for crop production. 
The crop most commonly grown on newly broken prairie sod in 
this region is winter wheat. There is probably no better preparation 
for this crop than that afforded by sod. When properly handled, 
sod is as good as or even better than fallow, and there is probably 
no better crop than winter wheat to raise on the sod for the first 
year or two. For the best result, sod should be broken between the 
middle of May and the middle of June. Sod broken earlier than 
the middle of May is subject to seeding by Russian thistles carried 
by the heavy winds of early spring. Breaking later than June 15 
restricts the prospective wheat yield by reducing the quantity of 
water stored in the soil after breaking stops the use of water by the 
grass. 
It is neither common practice nor good policy to break sod deeper 
than necessary to make the plow work well. The usual plowing 
depth in this short-grass sod is about 3 inches. A specially designed 
sod plow is almost a necessity. The sod slice should be turned com- 
pletely over and laid flat. If the plow does not turn the furrow 
slice over so that it lies flat, it is advisable to follow the plow with a 
heavy roller or a heavily weighted disk with the disks set straight. 
Sod lying flat holds moisture better and rots better than when on 
edge. 
It should not be necessary to cultivate the sod during the summer, 
but enough cultivation should be done before seeding so that the 
drill can cover the seed. Generally a good double disking and har- 
rowing is all that is necessary. The best seed bed is obtamed when 
the surface of the sod is fined without turning it over or loosening 
and roughening it by tearing it out of place. 
The foregoing statement applies to the treatment of sod as a fallow 
in preparation for winter wheat. It is often necessary to use sod 
land for a crop the first year. Sorgo and proso (hog millet) are well 
adapted to this purpose, and these, in wet seasons, will produce 
heavy crops of feed while in average seasons they will produce sat- 
isfactory crops. Such production is at least partly at the expense of 
the following crop, however. 
Pinto or Mexican beans have also been used successfully as a 
first-season crop on breaking. Winter wheat following beans is 
much more successful than when following sorgo. No attempt is 
made to intertill such crops as beans and sorgo when planted on 
prairie sod. 
SOIL BLOWING 
Soil blowing appears to become a more serious factor, especially 
with winter wheat, as more sod land is broken and as the land already 
under cultivation becomes more disintegrated and broken down 
from its original fresh-plowed condition. If the winter wheat does 
not emerge in the fall, or if it emerges too late to make any consid- 
* Colorado State Board of Immigration. Yearbook, 1923, 170 p., illus. 1923. 
