234 DRY-FARMING 
Moreover, while the various sections of the dry- 
farming territory are alike in receiving a small amount 
of rainfall, they are widely different in other conditions 
affecting plant growth, such as soils, winds, average 
temperature, and character and severity of the win- 
ters. Until trials have been made in all these varying 
localities, it is not safe to make unqualified recom- 
mendations of any crop or crop variety. At the 
present we can only say that for dry-farm purposes 
we must have plants that will produce the maximum 
quantity of dry matter with the minimum quantity 
of water; and that their periods of growth must be 
the shortest possible. . However, enough work has 
been done to establish some general rules for the 
guidance of the dry-farmer in the selection of crops. 
Undoubtedly, we have as yet had only a glimpse of 
the vast crop possibilities of the dry-farming territory 
in the United States, as well as in other countries. 
Wheat 
Wheat is the leading dry-farm crop. Every pros- 
pect indicates that it will retain its preéminence. 
Not only is it the most génerally used cereal, but the 
world is rapidly learning to depend more and more 
upon the dry-farming areas of the world for wheat 
production. In the arid and semiarid regions it is 
now a commonly accepted doctrine that upon the 
expensive irrigated lands should be grown fruits, 
