Dry-Farming

ts largely on the known relationship of the water requirements of plants to the natural precipitation of rain and snow. It is a m

he water thus taken into the plants is passed upward through the stem to the leaves, where it is finally evaporated.

within the plant, a certain amount of soil-moisture is also lost by direct evaporation from the soil surface. In dry-farm sections, soil-moi

one pound

taining weighed quantities of soil. As needed, weighed amounts of water were added to the pots. To determine the loss of water, the pots were weighed at regular intervals of three days to one week. At harvest tim

en selected and presented in the following table. The work was done by the famous German investigators, Wollny, Hellriegel, and Sorauer, in the early eighties of

r For One Poun

ellreige

t 33

665 3

ey 3

74 35

rn

heat

416

ebea

clov

lowe

let

he same under all conditions for the same plant. In fact, as will be shown in a later chapter, the water requirements of any crop depend upon numerous factors, more or

German experiments, to determine the water requirements of crops under Wisconsin conditions.

ts

ley

rn

as

ver

toes

uantity of water is required for the production of crops in Wisconsin as in Germany. The Wiscons

ming is likely to be practiced, a moderately high temperature, a cloudless sky, and a dry atmosphere are the prevailing conditions. It appeared probable therefore, that in arid countries the amount of water required for the production of one pound of dry matter would be higher than in the humid regions of Germany and Wisconsin. To secure informati

at

rn

s 1

Beet

water in a somewhat wasteful manner; that is, they were given an abundance of water, and used the largest quantity possible under the prevailing conditions. No attempt of any kind was made to economize water. The results, therefore, represent maximum results and can be safely used as such. Moreover, the methods of dry-farming, involvi

would be required to produce

pounds of water are required in an arid district for the production of one pound of dry matter. Where the aridity is intense, this figure may be somewhat low, and in

cing power

5,000 pounds of water. The wheat kernels, however, cannot be produced without a certain amount of straw, which under conditions of dry-farming seldom forms quite one half of the weight of the whole plant. Let us say, however, that the weights of straw and kernels are equal. Then, to produce one bushel of wheat, with the corresponding qua

sed wholly for plant production, it would produce, at the rate of 45 tons of water for each bushel, about 2-1/2 bushels of wheat. With 10 inches of rainfa

discussion of this chapter, the wheat-producing powers

ter will produce 2-

water will produce

water will produce 37

f water will produce

d soil-moisture may be used for plant production. Some moisture, of necessity, will evaporate directly from the soil, and some may be lost in many other ways. Yet, even under a rainfall of 12 inches, if only one half of the water can be co

" may be reclaimed by means of dry-farming. The real question before the dry-farmer is not, "Is the rainfall sufficient?" but