220 THE ESSENTIALS OF AGRICULTURE 



to these facts, the seeds are expensive and frequently scarce. 

 A remedy for part of the difficulty in cutting and curing the 

 vines for hay is to be found in sowing peas with some upright 

 crop, such as sorghum or corn, which serves to hold up the peas 

 and enables the crop to be cured and stacked much more con- 

 veniently. A mixture of one bushel of cowpea seed to one-half 

 bushel of sorghum seed to the acre is widely used in the South. 



288. The value of the hay. Cowpea hay varies greatly in 

 feeding value, according to the amount of grain it contains and 

 the way it has been cured. Hay from plants of average quality 

 easily ranks with clover in value, and the better grades of cow- 

 pea hay are quite the equal of alfalfa hay. 



289. The soy bean. The soy bean is an annual, and is be- 

 lieved to be native to southern Japan, China, Indo-China, and 

 Java. It has been in cultivation in China and Japan since 

 before the beginning of the Christian era, and in those coun- 

 tries it is the most important legume grown. The soy bean has 

 been known in the United States for almost a century, but it is 

 only within recent years that attention has been attracted to its 

 value in American agriculture. 



290. The vetches. The important cultivated vetches include 

 the common vetch (or tare), the hairy, sand, or Russian vetch, 

 and the purple vetch. There is a spring and a winter strain 

 of the common vetch. The principal production of vetch is in 

 western Oregon and western Washington, where it is grown 

 with winter wheat and winter oats as a hay crop. It is also used 

 in the citrus districts of southern California as a green-manure 

 crop, and in the Southern states to a limited extent as a forage 

 crop with winter oats. 



Other legumes of economic importance are white clover, a 

 perennial occurring abundantly in pastures ; alsike clover, a 

 perennial adapted to wet soils and maturing late enough to com- 

 bine well with timothy or redtop ; crimson clover, an annual 

 adapted to the south central Atlantic states and very valuable 

 as a green-manure crop ; and mammoth clover, a coarse, late- 

 maturing type of red clover. 



