FORAGE CROPS. 15 
serves to scatter the seed of the pest. The common system of farm- 
ing consists of taking a crop of wheat every alternate year, leaving 
the land idle every other year. During the idle year the land is sum- 
mer fallowed: that is, plowed up in spring and left bare during sum- 
mer. These fallow fields often furnish excellent wild-oat pastures, 
which are generally utilized. 
At the present time alfalfa, clover, and brome hay are beginning 
to take the place of grain hay in this wheat-growing section. It has 
been learned that an exhausted brome-grass field can be restored to its 
early vigor by plowing in winter and harrowing to good tilth. After 
this plowing, a crop of spring grain may be taken without serious 
injury to the brome grass. 
FORAGE CROPS. 
ALFALFA’ (Medicago sativa). 
GENERAL CONDITIONS. 
This well-known forage plant is extensively grown throughout the 
West in all localities where the conditions are suitable. It requires a 
well-drained soil and a fairly good supply of water, but will not endure 
an excess of water (standing water) near the surface. It thrives best 
where the summers are hot and dry and the winters not too cold. It 
will withstand a moderate amount of alkali in the soil. In the North 
it suffers in some localities from the effects of too cold winters, and is 
not usually successful above an altitude of 5,000 or 6,000 feet. It can 
be grown without irrigation in but comparatively few localities in the 
Northwest: but under irrigation it is extensively grown in all the 
States of this region, and reaches its greatest perfection in the hot, dry 
valleys of California, where the summer season is long, the water sup- 
ply abundant, and the soil well drained. Alfalfa will not succeed on 
acid soils, but these are of rare occurrence in the western part of -the 
United States. 
Alfalfa is a perennial leguminous plant, a native of western Asia, 
but cultivated in the Old World for ages. It was brought to Mexico 
by the Spaniards and from there spread into South America and north 
along the Pacific coast, and then throughout the interior arid and semi- 
arid regions. The name alfalfa, of Arabic origin, was given by the 
Spaniards and is in common use throughout western America. In 
Europe the same plant is known as lucern, a name which is common in 
the eastern United States, and also in Utah and the adjacent parts of 
Idaho and Wyoming. In the latter region the name is commonly pro- 
nounced with the accent on the first syllable. 
4 For further description see Farmers’ Bulletin No. 31. 
