North of parallel 40 deg., that is, north of the latitude of Columbus, Ohio, and Denver, Colorado, speaking in a general way, alfalfa is more commonly sown in the spring, but not usually so early as clover, lest the young plants, which are more tender than clover plants, should be nipped by spring frosts. This danger is frequently present in the region of the upper Missouri. East of the Mississippi it may usually be advisable to sow in the spring some distance south from the latitude named. West from the same are areas where early autumn sowing is frequently the best. In much of the Southern and Southwestern States, early autumn sowing is considered better practice than spring sowing, but to this there are exceptions. Under some conditions alternate freezing and thawing of the land near the surface tend to throw out young plants, as, for instance, those autumn sown, more readily than plants from spring-sown seed. Alfalfa is usually sown much the same as medium red clover (see page 75), but there are the following points of difference: 1. Since alfalfa is more commonly sown in dry areas, it is more important, relatively, that the seed shall be buried more uniformly and deeply in the soil in such areas. 2. Since it is liable to be more injured, relatively, by a nurse crop than the clovers, it is more frequently sown without one. And 3. Since it is expected to furnish food for a much longer term of years than any of the clovers, it is relatively more important that the seed shall be sown with a view to seek a uniform and sufficient stand of the plants. Whether the seed is sown by hand, or by any of the hand machines in use, the results will usually prove satisfactory, but in climates where moisture is deficient, decidedly better results are obtained from sowing the seed with some form of seed drill. A press drill is preferred in soils so light and open as to dry out easily or to lift easily with the wind. Under conditions of ample moisture, a light covering with a harrow will suffice, but under conditions the opposite, more covering is necessary. In areas where spring and early autumn showers are frequent, the roller will provide a sufficient covering, especially where the soils are well charged with a clay content. On other soils, as those which cover much of the prairie, the seed should be buried from 1 to 2 inches deep.