226 
ELEMENTARY AGRICULTURE 
growers of wheat have the habit of mixing several 
varieties, or paying very little attention to the variety 
at all. It is very desirable that each community grow¬ 
ing wheat for the market should develop one variety for 
that community. This should be kept pure by selecting 
out the best heads and growing them in seed plots until 
enough seed is produced for a field. Within two or 
three years, a pure strain of seed wheat may be had 
that will be adapted to the community and perhaps 
represent the highest yielding variety. 
Fig. 166 .—Drilling wheat. 
Soils for Wheat.—The soils for wheat are of no 
special type, if the moisture, fertility, and climatic con¬ 
ditions are favorable. Clay loam is the most common 
type in the wheat belt, but the grain is grown quite 
extensively upon soils adapted to corn. With the excep¬ 
tion of the early part of the growing season, wheat will 
grow with a very light water supply. A high yield 
depends upon a large amount of fertility in the top 
layer of soil, because the roots are shallow. 
