When the broadcast seeder is used in sowing clover seed, time is also saved as compared with hand sowing, but the seed can only fall before the seeder, and must, therefore, be given the same covering as the grain, as, when the seed is sown with the grain drill, it will in some instances be buried too deeply. In other instances it is not so.

The depth to which the seed of medium and other clovers ought to be buried should vary with soil and climatic conditions, and with the season of sowing. The more stiff the soil, the more moist the climate, and the earlier that the seed is sown, the less the covering required, and vice versa. As has been shown, under certain conditions (see [page 22]), early sown clover seed does not require any covering artificially given, and sometimes when sown later, a reasonably copious rain will provide sufficient covering, providing it falls quite soon after the sowing of the seed. But in certain of the soft, open, spongy soils of the prairie, it may sometimes be buried to the depth of at least 3 inches, with apparent benefit. Lower than 5 or 6 inches in any soil, clover seed will not germinate till brought nearer the surface. On all soils that lift with the wind, the seed should, as a rule, be buried deeply. Ordinarily, from half an inch to an inch, or an approximation to these distances, is considered a proper depth to bury clover seed.

Some authorities recommend sowing medium and other clovers without any nurse crop. The advantages claimed are that more or less of a crop may be obtained the same season, and that a stand of clover is more certain when the seed is sown thus. The first claim is correct in the main. In some localities favored with long seasons for growth, as in certain areas of Missouri, for instance, good yields may be obtained from sowing the seed thus. This has happened even in Minnesota. But in other areas and under other conditions, the yield would be light. In some localities, as, for instance, the Willamette Valley, Oregon, satisfactory returns have been obtained by sowing clover seed and rape seed in May and then pasturing both.

The chief objections to sowing clover seed thus are, first, that in a great majority of instances a sufficient stand of the plants may be obtained when the seed is sown with a nurse crop; and second, that when it is not thus sown, the first cutting of the hay will contain more or less of weeds. That a stand is more assured when clover seed is sown alone in areas where adverse weather conditions prevail cannot be disputed. Nevertheless, the fact remains that whenever in order to get a stand of a short-lived crop, like clover, it is necessary to sow it alone, and in many instances get but little return the same season, it will be well to consider if there is not some more satisfactory way of securing a crop that will prove an equivalent. In northerly areas the stubbles of the nurse crop frequently render substantial service to the clover by holding the snow on the crop, and also by protecting it more or less from the effect of the cold winds. The old-time practice of sowing clover with a nurse crop is likely to be continued, notwithstanding that it has some disadvantages.

These disadvantages include the following: 1. The young plants are liable to be weakened by the crowding and by overmuch shading from the grain when it grows rankly and thickly, and to such an extent that they perish; 2. When the grain lodges, as it frequently does, on rich ground, the clover plants underneath the lodged portions succumb from want of light; 3. Where the supply of moisture is low, in the struggle for the same between the stronger plants of the nurse crop and the weaker plants of the clover, the former secures the larger share. As a result, when the nurse crop is harvested, should the weather prove hot and dry beyond a certain degree, the clover plants will die. This is an experience not at all uncommon on the loose prairie soils of the upper Mississippi basin.

Injury from crowding and overshading may be prevented, or at least lessened, by pasturing the nurse crop with sheep for a time, at an early stage in its growth. The lodging of the grain may also be prevented by the same means. Injury from drought may also be lessened by cutting the crop at the proper stage of advancement, and making it into hay, as in the ripening stage of growth it draws most heavily on the moisture in the soil. The oat crop is the most suitable for being thus dealt with.

Clover seed may be sown with any of the small cereal grains as a nurse crop, but not with equal advantage. Rye, barley, wheat and oats are probably suitable in the order named. Rye shades less than wheat and oats and is harvested early; hence, its suitability for a nurse crop. Winter rye and winter wheat are more suitable than spring varieties of the same, since, on these the crop may usually be sown earlier, and the soil is likely to lose less moisture from surface evaporation. The marked suitability of barley as a nurse crop arises chiefly from the short period which it occupies the ground. Nor is the shade so dense as from grains that grow taller. Oats are the least suitable of all the crops named as a nurse crop, since they are characterized by a dense growth of leaves, which shut out the sunlight too much when the growth is rank. Notwithstanding, the oat crop may well serve such an end when sown thinly and cut for hay. Mixed grains grown together, as, for instance, wheat and oats, or a mixture of the three, answer quite as well for a nurse crop as clover and oats. The objection to them for such use arises from the fact that they are frequently sown more thickly than grain sown alone.

Clover may also be sown with flax or millet or mixed grains grown to provide soiling food. When the weather is moist, it is likely to succeed well with flax, as the latter does not form so dense a shade when it is growing as some other crops. But flax is usually sown so much later than these crops, that in some climates the dry weather following injures and in some instances destroys the young plants. The dense shade furnished by millet is also detrimental to the clover plants; nevertheless, owing to the short period which the former occupies the ground, under favorable conditions a stand of clover may be secured. But since millet is sown later than flax, it frequently happens that there is not sufficient moisture in the soil to sustain both crops. Mixed grains sown as soiling food are usually sown reasonably early, and as they are cut before maturity, the danger is so far lessened that the young plants will perish from want of moisture, but since these crops are usually grown thickly and on rich land, owing to the dense character of the growth, the plants are much more likely to be injured by the dense shade thus provided.

Clover seed may also be sown with corn and certain other crops that are usually grazed down, as rape and mixed grains. When sown with corn, the seed is usually scattered over the ground just before the last cultivation given to the corn. Attention is now being given to the introduction of cultivators which scatter such seeds as clover and rape in front of them, and so preclude the necessity for hand sowing. From Central Ohio southward, this method of securing a stand of clover will succeed in corn-growing areas, the other conditions being right. North from the areas named, the young clover plants may be winter killed when the seed is sown thus. The less dense the shade furnished by the corn, and the less dry the weather subsequently to sowing the seed, the better will be the stand of the plants secured.

When sown with rape that has been broadcast, clover usually makes a good stand, providing the rape crop is not sown too late in the season. When the rape is grazed down, the grazing does not appear to materially injure the clover, and when the shade has been removed by such grazing, the clover plants may be expected to make a vigorous growth on such land. In northerly areas, clover seed may be sown along with rape seed as late as the end of May. If sown later than that time, the season may prove too short subsequently to the grazing of the rape to allow the plants to gather sufficient strength to carry them safely through northern winters. When clover seed is sown with rape, the seeds may be mixed and sown together.