Any direct application of fertilizer is usually made at seeding time, but some few farmers have been found who apply it as a top dressing very early the following spring, giving as a reason that there is no loss from winter leaching and that the plants are by this method nourished at the time they are making their most vigorous growth. Such top dressings of fertilizer should not be made while the leaves are wet with rain or dew. Where stable manure is applied to crimson clover very marked results follow. It may be spread just before seeding, when the clover is not grown in an intertilled crop, or it may be applied as a top dressing in winter or very early spring.
The more vigorous the growth that can be induced by the application of suitable fertilizers the more marked will be the increase in the yield of the succeeding crops. On soil not well supplied with humus or plant food the use of a reasonable amount of fertilizer will often enable a successful crop of clover and succeeding crops to be produced where, had not the fertilizers been applied, the clover would have failed. Furthermore, the following crop, particularly if it be corn, would also fail to give the increased yield which follows a successful stand of crimson clover.
An application of barnyard manure will be found to be especially effective in obtaining a stand of crimson clover on any thin, galled spots in the field. The manure should be worked into the ground and, if possible, a second application as a top dressing should be given such thin places to partially shade the ground from the August sun while the seedlings are establishing themselves.
LIMING SOILS FOR CRIMSON CLOVER.
Most of the soils in the crimson-clover sections will be found to be benefited by liming. Crimson clover, however, does not appear to require lime to the extent that red clover does. Frequently on well-drained soils in a good state of fertility the crimson clover makes a vigorous growth without the use of lime. The stands are, however, usually more uniformly good over the limed parts of such fields than on the parts that have received no line. The opinion among individual farmers appears to be about equally divided as to whether or not it pays them to lime their soils for crimson clover. In considering the advisability of applying lime one must not lose sight of the need of lime on the part of such other crops as cantaloupes or peaches, which require lime and which are either grown with the clover or follow it. Inasmuch as the extent of the benefit is somewhat uncertain it is suggested that the particular requirements of the farm in question be determined by liming small plats at different rates before any considerable areas are limed. The most profitable rate of application can then be adopted for the whole acreage.
INOCULATION FOR CRIMSON CLOVER.
Fortunately most of the soils in the crimson-clover sections appear to be already inoculated. This is especially true in sandy soil areas where crimson clover has been grown for a number of seasons. In sections new to this crop inoculation in some form is usually necessary. On clay soils inoculation is not always present, even though crimson clover may have been grown, for a number of successive seasons on other fields of the farm.
An experiment conducted by the Alabama State Agricultural Experiment Station shows how essential inoculation is on soils which have not previously grown crimson clover. In this experiment a yield of 4,057 pounds of crimson clover hay was secured where the plants were inoculated, as compared with only 761 pounds where no inoculation was provided. In another test by the same station the inoculated plat of crimson clover yielded at the rate of 6,100 pounds of cured hay per acre, while the uninoculated plat was a total failure.
Inoculation by the use of soil from a crimson-clover field is considerably more certain than is inoculation by the use of pure cultures, but soil inoculation is open to the danger of introducing noxious weeds, insects, and plant diseases, especially if the soil is brought from a distance. There is much less danger in this respect if soil from inoculated plants can be obtained in the same neighborhood. One very practicable method is to apply a bottle of pure culture[3] to a pound or two of the seed and sow this in the corner of some field, or even in the garden. The resulting plants will be quite sure to be inoculated and will furnish an abundant supply of soil for inoculating much larger areas at the next seeding. Care must be taken not to allow the sun to shine upon either the pure cultures or the soil, or even on the seed after it is broadcasted. For this reason it is safest to seed on a cloudy day or after sundown. One very satisfactory method of soil inoculation consists merely in mixing together equal parts of the proper soil and seed and sowing immediately in front of the covering harrow.
[3] Pure cultures are sent free by the U. S. Department of Agriculture. Full instructions for using them accompany each bottle.