ry 
HAIRY-VETCH SEED PRODUCTION. 9 
SUPPORT CROPS. 
Whether for hay or seed, hairy vetch rarely is grown alone, but 
nearly always in combination with some grain crop to hold it off 
the ground. For seed production, winter rye is used almost exclu- 
sively. Spring wheat, oats, or.barley sometimes is drilled into 
thin stands of hairy vetch im the spring in order to produce hay. 
Occasionally they are allowed to produce seed, but as they ripen 
several weeks later than hairy vetch the vetch is apt to shatter 
badly before the grain is ready to harvest. 
Rye and hairy vetch form a very useful combination, having 
somewhat the same relation to each other as timothy and red clover. 
Both are outcasts of the wheat field and neither is very profitable by 
itself. When grown together, however, the mixture has many 
advantages. The growing period of the two plants is practically 
identical except that hairy vetch must be planted a few weeks earlier 
than is absolutely necessary for rye. The rye plant is tall and 
strong and holds up the hairy vetch nicely, and it is believed that 
the vetch by adding nitrogen to the soil increases the growth of 
the rye. The plants are harvested and thrashed together, the com- 
bined yield being greater than either crop alone. The presence of 
hairy vetch adds to the feeding value of the rye straw, which would 
otherwise be difficult to utilize. Thus, by the partnership neither 
plant is injured, but each is helped by the presence of the other. 
In recent years, an important development in growing rye and 
vetch together has been the introduction of improved varieties of 
rye, particularly the Rosen rye. This variety commonly outyields 
ordinary rye and is consequently more profitable. A further advan- 
tage is that the straw of Rosen rye is somewhat shorter and stiffer 
than that of ordinary rye, while the seeds are a few days later in 
ripening, thereby allowing more time for the vetch to mature. The 
only objection to Rosen rye is that the kernels are plumper and 
more nearly round than those of ordinary rye and hence are slightly 
more difficult to separate from the vetch. 
USE IN THE ROTATION. 
When hairy vetch is grown especially for seed, it must become 
part of a regular crop rotation. It can not be grown merely as a 
catch crop to be fitted into the cropping system at odd seasons. 
When hairy vetch is grown for hay or green manure it is usually 
out of the way by the middle or last of May, in time for planting 
corn or any late-planted summer crop. The seed crop, however, is 
not harvested until July or August, at which time there is no chance 
for another crop that season. 
Hairy vetch for seed is sown with rye, and the mixture is handled 
in practically the same manner as rye grown by itself. The crop 
183944°—20—Bull. 8762 
