Early varieties of the soybean in the south can be
planted as late as mid-summer, but farther north a profitable crop
requires nearly all of the summer heat. The planting may be made soon
after the usual time of planting corn, or whenever the ground has
become warm. The preparation of the soil should be more thorough than
that often given the cowpea. Solid drilling of five pecks of seed per
acre is satisfactory when the crop is for fertilizing purposes only,
and gives an excellent hay on land free of weeds. When the crop is
wanted for hay, however, wheat usually will follow, and it is much
better to plant in rows and to give two or three cultivations so that
the ground may be easily prepared for the wheat.
A seed crop should be grown in rows. Three pecks of seed in rows 28
inches apart is the usual amount.
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.