The nurse crops with which clovers may be sown are the small cereal grains, as rye, barley, wheat and oats. Sometimes they are sown with flax, rape and millet. They usually succeed best when sown along with rye and barley, since these shade them less and are cut earlier, thus making less draft on moisture in the soil and admitting sunlight at an earlier period. Oats make the least advantageous nurse crop, because of the denseness of the shade, but if they are sown thinly and cut for hay soon after they come into head, they are then a very suitable nurse crop. One chief objection to flax as a nurse crop is that it is commonly sown late. The chief virtue in rape as a nurse crop is that the shade is removed early through pasturing. The millets are objectionable as nurse crops through the denseness of the shade which they furnish and also because of the heavy draught which they make on soil moisture. Peas and vetches should not be used as nurse crops, since they smother the young clover plants through lodging in the advanced stages of their growth. =Amounts of Seed to Sow.=--The amounts of clover seed to sow are influenced by the object sought in sowing; by combinations with which the seeds are sown, and by the relative size of the seeds. The soil and climate should also be considered, although these influences are probably less important than those first named. When clovers are sown for pasture only, or to fertilize the soil speedily and to supply it with humus, the largest amounts of seed are sown. But for these purposes it is seldom necessary to use more than 12 pounds of seed per acre. These amounts refer to the medium red and mammoth varieties, which are more frequently used than the other varieties for the purposes named. They also include the crimson sown usually to fertilize the soil. When sown to provide seed only, 12 pounds per acre of the medium red, mammoth and crimson varieties will usually suffice. Half the quantity of alsike will be enough, and one-third the quantity of the small white, or a little more than that. Whether alfalfa is grown for seed, for hay or for pasture, about the same amounts of seed are used; that is, 15 to 20 pounds per acre. When sown with nurse crops and simply to improve the soil, it is customary to sow small rather than large quantities of seed, and for the reason that the hazard of failure to secure a stand every season is too considerable to justify the outlay. From 4 to 5 pounds per acre are frequently sown and of the medium or mammoth variety.