Crimson clover has been an important factor in increasing yields on soils that have been abused, but it is not a crop for land which is naturally very poor. It does not do well on rough, newly cleared areas, raw subsoil, Hard, dry clay, or sterile sand. ([Fig. 4.]) For such soils soy beans, cowpeas, and velvet beans are better suited and should be used for the first three or four years until crimson clover can be successfully grown. Crimson clover can be made to grow on poor soils, provided they are specially prepared by liming, manuring, and inoculating. In general, however, crimson clover is a crop for maintaining soils which are already fairly productive rather than one for inducing productivity in soils where it is quite lacking. If there is any doubt whether the soil is suitable for crimson clover, a small plat should be prepared under field conditions and planted one year for trial.
PREPARATION OF THE SEED BED.
To secure a full, even stand of crimson clover with any degree of regularity the seed bed should be well and thoroughly prepared. The soil should be firm, moist, well settled, and fine on top. Only indifferent success can possibly be expected if the seed is scattered on land which is loose, dry, and full of hard lumps and trash. A loose seed bed dries out quickly, heaves during the winter, and on some soils blows and washes badly.
Fig. 5.—A corrugated roller or pulverizer, an excellent implement for preparing the seed bed for crimson clover.
On the other hand, the seed bed should not be too hard, for although this clover often grows successfully on soil which would be too solid for corn, there must be at| least enough loose soil on the surface to cover the seed. Thorough preparation is the very best insurance against failure of the stand through drought or winterkilling, and the most successful growers sow crimson clover on land as well prepared as that for wheat.
To secure a fine, firm seed bed without drying out the surface soil, the land should be prepared with as few operations as possible. A single working when the soil is in a moist, crumbly condition is better than half a dozen workings when the soil is too wet or too dry. In very sandy soils, or soils which do not form a crust, the only preparation needed is to keep down the weeds.
An excellent tool for making the seed bed is the corrugated roller or pulverizer ([fig. 5]). This implement is an improvement over the old plain roller for breaking clods and is unexcelled for keeping the surface soil moist. It can be used after plowing and again before planting, and even after planting if the soil needs to be compacted. Rolling of some kind to firm the soil is especially important on sandy soils, but it is equally beneficial on clay soils if they are cloddy.