In order to protect the crimson-clover seedlings from the hot sun of late August it is a common practice in some sections to plant with the clover a small quantity of some quick-growing crop like buckwheat, cowpeas, rape, or turnips. A thin stand of these heavier leaved plants furnishes an ideal shade for the young clover, and on soils which are inclined to bake it prevents the formation of a crust. The nurse crop must be seeded lightly, usually not more than half the regular rate, as the ordinary stand shades the ground so completely as to destroy the crimson clover. On hot clay soil in the Piedmont region the chances of obtaining a stand of clover are about twice as good with a nurse crop as without one.
Buckwheat is the principal nurse crop northward from Washington, D. C. A common rate of seeding is 2 to 3 pecks of buckwheat in 15 pounds of crimson clover. If the planting can be made in July the buckwheat usually has time to ripen before frost and thus pay the cost of starting both stands.
In the cotton belt cowpeas have been used successfully, especially when seeding on fallow ground. They are seeded broadcast at the rate of one-half bushel per acre. There is ordinarily not enough time for the cowpeas to mature, but they add to the value of the stand for fall pasturage and protect the clover from severe weather in the winter. Both cowpeas and buckwheat have the merit of being able to grow on poor soil.
Dwarf Essex rape has been used as a nurse crop in a few cases where the clover was to be pastured by hogs or sheep in the fall. From 2 to 3 pounds of rape, sown in August, furnishes sufficient cover for a nurse crop. Cowhorn turnips, winter kale, and mustard are also satisfactory nurse crops if planted at a rate not exceeding 1 pound of seed per acre. If the clover is to be saved for seed these latter crops are objectionable, as a few plants will live over winter and ripen at the same time as the clover.
Where a nurse crop can not be grown conveniently, the crimson-clover seedlings can be protected from the sun by a light top-dressing of straw, spread just after the seed is sown.
SEED MIXTURES.
Crimson clover is frequently grown in combination with winter grain, hairy vetch, or other forage crops having a similar period of growth. The mixed crop is less liable to lodge than the single crop, cures more readily in damp weather, and usually furnishes a heavier yield. Another advantage of the mixed crop is that if either should fail the other will serve as a cover crop during the winter and bring some return the following spring. Mixed crops are not desirable if the clover is to be saved for seed.
South of central Virginia crimson clover is usually grown in combination with winter oats. An early variety of oats, such as the Fulghum, or a late variety of clover, such as the white blooming, is usually the best, as the oat crop matures somewhat later than the ordinary crimson clover. The customary rate of seeding is 15 pounds of the clover and 2½ bushels of oats per acre. In Delaware and eastern Maryland the most popular companion crop for crimson clover is winter wheat, although barley makes a desirable hay crop and is sometimes used. Eye is not desirable for hay, but it is probably the best of the grains for green manure, as it is hardy, vigorous, and starts growth early in the spring. Rye and wheat are seeded at the rate of 1 bushel per acre with the customary quantity of crimson clover. The accompanying illustration ([fig. 8]) shows a field seeded to a mixture of crimson clover and wheat. Usually the grain is well headed, but in the milk or soft-dough stage, when the clover is ready to cut, the yield of the mixed crimson clover and grain is often 25 to 50 per cent greater than that of the clover alone.
