Prev | Current Page 98 | Next

Widtsoe, John Andreas, 1872-1952

"Dry-Farming : a System of Agriculture for Countries under a Low Rainfall"

Leather found that in the calcareous arid
soil of India the upper 5 feet contained 18 per cent of water at the
close of the wet season.
It may be concluded, therefore, that the field-water capacities of
ordinary dry-farm soils are not very high, ranging from 15 to 20 per
cent, with an average for ordinary dry-farm soils in the
neighborhood of 16 or 17 per cent. Expressed in another way this
means that a layer of water from 2 to 3 inches deep can be stored in
the soil to a depth of 12 inches. Sandy soils will hold less water
than clayey ones. It must not be forgotten that in the dry-farm
region are numerous types of soils, among them some consisting
chiefly of very fine soil grains and which would; consequently,
possess field-water capacities above the average here stated. The
first endeavor of the dry-farmer should be to have the soil filled
to its full field-water capacity before a crop is planted.
Downward movement of soil-moisture
One of the chief considerations in a discussion of the storing of
water in soils is the depth to which water may move under ordinary
dry-farm conditions.


Pages:
86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110