The soybean does not come up through a crusted surface as well as most other plants, and planting should not be made immediately before a rain. The plants are tender and easily injured by use of a weeder.
The fertilizer requirement is like that of the cowpea. An application of 200 pounds of acid phosphate per acre should be given, and the addition of 50 pounds of muriate of potash often pays.
Harvesting.—The soybean is not an easy crop to handle without loss. When grown for seed, the tendency of the pods to split and to drop the seed compels early cutting, and that makes curing more difficult. The mower is the only practical harvester on most farms, and the swath must be turned out of the way of the horses to save tramping. A side-delivery attachment can do the work. This is the best practice when cut for hay. When used for mixing with corn in a silo, the self-binder is satisfactory. The hay and seed crop must have thorough field-curing in windrow and bunches, and the harvest comes in a season when cold rains may prevail. This disadvantage of one of our most valuable crops is to be taken into account, but it will not prevent rapid increase in acreage as the merit of the soybean becomes known.
The Canada Pea.—Among field peas there are many varieties, but the one chiefly grown in the United States under the general name of the Canada pea is the Golden Vine. It makes a green forage or hay that is rich in protein. Usually it is grown with oats, giving a hay nearly as nutritious as that of clover. The crop is adapted to cold latitudes, and the planting should be made as early in the spring as possible. Fall-plowing of the land is to be advised on this account. A good method of seeding is to drill in six pecks of the pea seed to a depth of four inches, and then to drill in six pecks of oats.
The crop should be cut for hay when the oats are in the milk stage. At this time the peas are forming pods. The hay is not easily made, but is specially valuable for dairy cows.
There is no profitable place for the Canada pea in crop-rotations farther south than the true oat-crop belt, except as a green-forage crop. The soybean and red clover have greater usefulness in the center of the corn belt.
Vetch.—A variety of vetch known as winter, sand, or hairy vetch is coming into great usefulness as a catch crop. It is a winter annual, and being a legume, it has special value as a fertilizing crop. It is more hardy than crimson clover, and is grown as far north as winter wheat. The seeding is made in August in the north, and when grown for hay or seed, it needs rye or wheat to hold it up. Rye and vetch make a rich and early green forage crop, and the proportion in which they are seeded varies widely in practice. Six pecks of rye and 15 pounds of vetch make an excellent seeding per acre.
When grown for seed, one to two pecks of rye and 20 to 30 pounds of vetch may be used. The rye can be fairly well separated from the vetch by use of a fanning-mill or an endless belt of felt so inclined that the round vetch seed will roll down, while the rye sticks to the felt and is carried over.
Vetch is excellent as a fertilizing crop, adding a great amount of nitrogen to the soil when plowed down in May. If the seed were cheap, its use would become much more common. Thirty pounds should be used when seeding alone after summer crops or in corn. Farmers should produce the seed for their farms, and use it freely. When sown for seed, September first is a good date for the north. The seed matures in June.
As vetch matures with wheat, it may easily become a weed on farms devoted largely to small grain, but it is not to be feared where tilled crops and sods are the chief consideration. Inoculation is needed for best results, as in the case with other legumes new to a region.