8 BULLETIN 876, U. S. DEPARTMENT OF AGRICULTURE. 
On the other hand, seed production should not be attempted 
where the soil is too poor; under such conditions the plants lack 
vigor and produce a small crop of low-quality seed. This mistake 
has sometimes been made in north-central Michigan on the light blow 
sands and jack-pine plains, where the soil is almost pure sand and 
contains practically no organic matter. For a few years after the 
land is cleared these soils produce fairly good crops, but unless steps 
are taken to renew the humus, the original supply is soon exhausted 
and the soil becomes barren. 
Some of the best crops of hairy-vetch seed in Michigan are grown 
on poor sandy land which has been rejuvenated. The process of 
rejuvenation is slow, however, and vetch must be grown for several 
years before a profitable stand can be expected. The first year after 
planting, only a few scattered plants appear, regardless of how 
heavily the seed is sown. The stand improves somewhat during 
the second and third years, but it is not until the fourth or fifth year 
that a full stand can be secured. After that, if the soil is at all 
suited to the crop, the yield of seed will be quite regular, although 
never equaling that obtained in richer areas. 
The conclusion is quite clear that no attempt to grow hairy vetch 
either for forage or seed should be made by the settler on poor sandy 
lands unless he is prepared, financially and otherwise. to wait several 
years for a crop. 
Hairy vetch is less sensitive to acid soil than red clover, but soils 
which are excessively “‘sour’’ must have applications of lime. A 
total of 1,500 pounds of hydrated lime or 2,000 pounds of finely 
ground limestone per acre applied and worked thoroughly mto the 
soil just before the rye and vetch are sown, usually will be found 
very beneficial. . ; 
No experimental data are available to show whether commercial 
fertilizers can be profitably applied to the hairy-vetch seed crop. 
Nitrogenous fertilizers probably are not desirable, but it is believed 
that phosphoric acid and potash applied to the rye have a beneficial 
effect on the hairy vetch as well. 
INOCULATION. 
A frequent cause of failure in growing hairy vetch is lack of inocu- 
lation. This is indicated by a yellow, sickly condition of the plants 
and the absence of nodules on the roots. The proper nodule-forming 
organisms are usually present in any field where garden peas, field 
peas, sweet peas, or any of the vetches have grown successfully, 
and they can be introduced into another field by transferring soil 
from these fields. Laboratory cultures of the inoculating organism 
also can be used.’ 
2 Pure cultures of inoculating organisms can be obtained from dealers, or in small quantities they may be 
procured without cost upon application to the United States Department of Agriculture or to the State » 
agricultural experiment stations. 
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