114 DESCRIPTION OF FEEDING STUFFS 
a hopeful sign of agricultural progress in this country. The legumes 
furnish the cheapest sources of nitrogen and nitrogenous feed com- 
ponents available to the farmer, and by their culture he will, in a 
measure, become independent of both fertilizer and feed manu- 
facturers. 
The most important species of the legumes adopted for feed- 
ing farm animals are clover (red, mammoth, alsike, white, crimson, 
wen Japan), cowpea, soybean (Fig. 
15), vetch, pea, bean, beggar 
weed, and peanut. Brief men- 
tion will be given in the follow- 
ing pages of these different 
species that are of special im- 
portance as forage crops. 
Alfalfa (Medicago sativa)® 
(Fig. 16) is one of our most 
valuable forage plants. In the 
western part of the United 
States it ranks first in impor- 
tance as a soiling and hay crop. 
It was introduced into Cali- 
fornia from Chili in 1854, and 
gradually spread over the irri- 
gated regions of the West, and 
from there eastward, until it is 
now grown in every State in 
the Union, as well as in Canada. 
It requires a deep, well-drained 
and fertile soil, with a perme- 
Fie. 15.—A soybean nitrogen factory. The able subsoil, for its best develop- 
acteria te the root nodules into'forme thar Ment, and under optimum con- 
are ved by the host plant for the elaboration ditions will yield enormous crops 
of forage. Several cuttings are 
obtained during the season from alfalfa fields, the number increas- 
ing from two to six or more as we go southward. The highest 
yields are obtained on the irrigated land in southern California 
and the southwestern States, where eight to ten tons of hay per 
acre are frequently obtained. As it generally takes about four tons 
of green alfalfa to make a ton of hay, this corresponds to a yield of 
forty.tons of green alfalfa per acre. Good alfalfa fields in the 
humid regions will yield at the rate of four to five tons of hay per 
f 
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