DRY FARMING. The phrase ((dry farm is a misnomer, for it implies the growing of crops without the use of water, which is alto gether impossible. But in United States terri tory west of the 97th meridian, in that region once familiarly known as The Great American Desert, the phrase is popularly used to describe all those efforts that are made to produce crops without irrigation.
Dry farming is the careful culture of the soil to the end that as large a percentage as possible of the moisture that falls be made available for the growth of the plant, instead of passing off into the atmosphere by evaporation.
The assumption behind dry farming is that moisture sufficient falls, if it can be conserved in the soil, to produce a great variety of crops where it is commonly supposed that precipita tion is inadequate to supply the moisture needed by a growing crop.
It has been demonstrated after many years of experimental work in places widely scattered in what is known as semi-arid America that a very large percentage of the moisture that evaporates from the soil can be conserved by intensive cultivation of the soil. If the soil is tilled intensively 12 inches of precipitation are sufficient in the semi-arid portions of the United States to produce crops adapted to a particular locality. Over a very large portion of the semi arid area of America the annual precipitation ranges from 12 to 24 inches.
The importance of dry farming in the eco nomic development of the western part of the United States may be appreciated when it is known that more than one-third of the total land area of the nation is contained within the area once known as The Great American Desert and now called semi-arid America. There are upwards of 600,000,000 acres in this region, a goodly portion of which can be made useful for agriculture by now known methods.
There was formerly a popular idea to the effect that precipitation in what is known as the semi-arid regions of the United States was not sufficient to make agriculture possible and profitable. This idea is erroneous. Over more
than half the total semi-arid area— the north ern half — the annual precipitation in form of both rain and snow is sufficient, when coupled with intensive soil culture and seed selection, to make general farming as great a success as it now is in the great prairie states of the Middle West.
Summer purpose of sum mer culture is to store up in the soil one sea son's moisture before a crop is planted, though it does not follow that no crop should ever be planted on newly-broken prairie. In fact a crop of peas does very well on such land and the same fall a crop of wheat may be planted with excellent results, if surface cultivation is carried on the following spring before the wheat is very high.
If the field is summer tilled for the purpose of storing moisture,, it should be plowed again about eight or nine inches deep. This time the plow should be followed by an implement with wedge-shaped wheels turning on an axle known as the subsoil packer. It presses the soil down ward and sideways at the same time, but it does not pack the surface It leaves this loose and open and the harrow completes the work of creating the soil mulch again.
This sub-surface packing is regarded as very important. All water moves in the soil as oil moves up a lamp wick, by what is known as the process of capillarity. If the solid soil column is interrupted or broken by large air spaces be neath the surface, the movement of the moisture will be interrupted, and large air spaces in the sub-soil tend to increase the evaporation, for they suck up the moisture from below.
It is not considered absolutely necessary to the success of dry farming to summer till for one whole season in advance of planting a crop as outlined here. But unless the farmer in tends to devote himself assiduously to the cultivation of the acreage which he plants after carefully preparing The seed bed, it would be far better to summer till — that is, produce no crop the first season but harrow the ground fre quently and store the moisture that falls.