It is unfortunate that the
study of the dry-farming territory of the United States has not
progressed far enough to permit a comprehensive and correct mapping
of its soils. Our knowledge of this subject is, at the best,
fragmentary. We know, however, with certainty that the properties
which characterize arid soils, as described in this chapter' are
possessed by the soils of the dry-farming territory, including the
five great districts just enumerated. The characteristics of arid id
soils increase as the rainfall decreases and other conditions of
aridity increase. They are less marked as we go eastward or westward
toward the regions of more abundant rainfall; that is to say, the
most highly developed arid soils are found in the Great Basin and
Colorado River districts. The least developed are on the eastern
edge of the Great Plains.
The judging of soils
A chemical analysis of a soil, unless accompanied by a large amount
of other information, is of little value to the farmer. The main
points in judging a prospective dry-farm are: the depth of the soil,
the uniformity of the soil to a depth of at least 10 feet, the
native vegetation, the climatic conditions as relating to early and
late frosts, the total annual rainfall and its distribution, and the
kinds and yields of crops that have been grown in the neighborhood.
Pages:
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81