Sweet clover, as ordinarily handled, is a rotation or temporary pasture plant. It is grazed from midsummer of the first year until midsummer of the second year, when it matures. The animals must then be shifted to another field containing a new seeding. This practice is a common and profitable one and probably provides more high-grade pasturage per acre than any other common system of grazing. Every field, however, must be well fenced and there must be lanes connecting them. Every field also must have water and shade. Some of the fields often are far from the barns. Most important, dependence must be placed each year on a new seeding, and seedings sometimes fail. Consequently, much interest is expressed in means of utilizing sweet clover in fields of more or less permanent character.

The simplest plan is to plant a field with sweet clover and permit the crop to go to seed. After several years the surface soil becomes so full of sweet clover seed that a volunteer crop appears each year. Fields of this kind, which have been in sweet clover continuously for 10 or more years, are not uncommon. The chief objection to the plan is that, unless grazed very heavily, the fields do not contain young and old plants in the right proportion to give continuous feed. In both wild and cultivated stands, if at all dense, the second- year plants smother the seedling plants and the two rarely occur together. To overcome this condition seed is sometimes sown each year for the first three or four years, but this does not help greatly, except to build up a stand more quickly.

FIG. 218.—A pasture consisting of sweet clover and quack grass that has been grazed heavily with sheep for three years

FIG. 219.—A field in Oklahoma that has been in sweet clover continuously for 5 years and supports nearly 1 animal per acre for 5 months, Adjacent grass pastures support 1 animal on 2 acres for 6 months

Yellow Variety Finds Favor

A better plan is to divide the field in halves and plant and graze them alternately. By many it is believed that the yellow sweet clover is better adapted to permanent grazing than the white variety, because it produces seed freely, even if pastured close to the ground. By others a mixture of the two varieties is favored as this lengthens the pasturing season 7 to 10 days at each end.

Sweet clover may often be used to improve the carrying capacity of an old or worn-out grass sod. In doing this it is necessary to bring the sweet clover seed actually into contact with the soil. If the seed is merely scattered over the sod, most of it is held off the soil by the old grass and only a few seedlings take root. On tillable land the seed can be cut into the sod with a disk drill. Another plan is to burn off the old grass in the spring before sowing the seed. On western prairie sod a good practice is to plow wide but shallow furrows through the sod about 3 feet apart. This provides fresh soil on which to sow the seed. The presence of the sweet clover gradually improves the grass.

Pastures of excellent quality that last several years may be made by sowing mixtures of sweet clover and other forages. One such mixture contains 2 pounds yellow sweet clover, 2 pounds white sweet clover, 3 pounds orchard grass, 2 pounds redtop, and 1 pound Kentucky bluegrass. Brome grass should be substituted for the other grasses in the northern Great Plains and Japan clover for the redtop and bluegrass in the Southern States.