10 - BULLETIN 6, U. S. DEPARTMENT OF AGRICULTURE. 
COWPEA. 
For a century the cowpea, of many varieties, has been the chief 
leguminous crop of the Southern States, grown for hay, for its edible 
seeds, and as a green manure. Only recently has its resistance to 
acidity been recognized. The experiment stations have carried the 
plant much farther north in the past few years, until now some of 
the varieties are in successful cultivation in Massachusetts. New 
York, and Michigan. Sometimes the yield of tops is so dense and 
heavy that only by the use of special attachments to the plow can 
the crop be turned under. 
SOY BEAN. 
The soy bean is of much more recent introduction into the United 
States than the cowpea. In its tolerance of acidity the soy bean 
probably equals the cowpea, and it has two points of superiority. 
It grows farther north and its yield of seed is much greater, often 
being as high as 30 bushels per acre. Some of the varieties have 
been grown with success as far north as New Hampshire, Ontario. 
and Wisconsin. The seed of the soy bean has one remarkable char- 
acteristic. It contains no starch, but about 35 per cent of nitroge- 
nous matter. Such a composition ought to give these beans a special 
value in rations for cattle. Within the climatic limits of its profit- 
able cultivation this plant may prove to be exceedingly valuable on 
the acid dairy farms of New England, where enormous sums are 
spent for the purchase of southern and western nitrogenous cattle 
feeds. 3 
HAIRY VETCH. a 
Hairy vetch differs in one conspicuous feature from the cowpea 
and soy bean. Both these plants are sown in the spring or early 
summer and mature and die in the fall of the same year, but the 
hairy vetch is what is known as a winter annual. It is sown in late 
summer, germinates at once, passes the winter as a small plant, 
makes a heavy growth in the following spring, and matures its seed 
in early summer. It so closely accords in season with rye that the 
two form an ideal mixture when the rye is to be plowed under for 
green manure or cut for early hay. 
CRIMSON CLOVER. 
Crimson clover is a leguminous plant that does well in sandy soils 
from New Jersey southward. It appears to be tolerant of acidity 
and may come to be definitely recognized as a plant of this class. 
The seed is sown in late summer, becomes well established before 
winter, makes a luxuriant growth in early spring, and is ready for 
the scythe or the plow in May. 
