16 CULTIVATED FORAGE CROPS OF THE NORTHWEST. 
Being a legume, it gathers nitrogen from the air by means of its 
root nodules, and hence acts as a soil renovator. Although alfalfa is 
a perennial, a field usually deteriorates after a few years from various 
causes. Fields in California as much as 27 and in Nevada from 35 to 
40 years old are reported, but in most cases they require renewing 
much earlier. Oxten the alfalfa fields become infested with weeds. 
The squirrel-tail grass (fordeum jubatum)—also called foxtail in 
Wyoming, barley grass in Utah, and tickle grass in Nevada—is com- 
mon in alfalfa fields of the Great Basin and Wyoming plateau region, 
and wild barley (/fordewm murinum)—also called barley grass and fox- 
tail—on the Pacific slope. 
These two grasses are especially troublesome on account of the long 
bristles attached to the chaff. When mature they cause serious irrita- 
tion in the mouths of animals eating hay containing the weed. In the 
Cache Valley and in western Wyoming the common dandelion is very 
troublesome. It thrives along irrigation ditches and invades the 
alfalfa fields to such an extent that usually the fields are plowed up in 
from five to eight years and renewed. This is done in the fall and 
oats are sown the following spring, after which the fields are again 
seeded down to alfalfa. 
Many express the opinion that under favorable conditions an alfalfa 
field will last indefinitely and continue to yield profitable crops if 
properly handled; but the alfalfa may be killed in spots due to the 
trampling of stock if a field is overpastured, or, during irrigation, 
certain portions of the field being lower, may remain saturated with 
water for too long a period. Alfalfa will scarcely survive standing 
water longer than forty-eight hours. When alfalfa dies, its place is 
likely to be taken by the before-mentioned pernicious weeds. 
Some growers renew their fields by disking the bare spots in the 
spring and sowing seed thereon, or even disking the whole field. Disk- 
ing is to be recommended, as it cuts the crowns vertically and causes 
them to send out new stems. 
FEEDING VALUE. 
In the great alfalfa districts of the West this forage plant furnishes 
the chief and often the only food for stock besides the native pasture. 
It is fed to growing stock and to fattening stock; to cattle, sheep, 
horses, and hogs; even the work horses upon the ranches may receive 
no grain in addition to the allowance of alfalfa. Horses that are 
worked hard upon the road, such as livery teams, usually receive a 
small quantity of barley, and this grain may form a part of the ration 
for the work horses upon the ranches. Rolled barley is the form in 
which it is usually fed, as in this condition there is said to be less 
waste than when whole or ground. For this purpose the grain is 
passed through heavy rollers, which crush it without grinding it. 
