While some varieties of clover may be grown in various rotations and with profit, one of the best of these, where the conditions are favorable, is a three years' rotation. The first year some small cereal grain is grown and clover is sown along with it or, at least, on the same land. The next year the clover is grown for hay or pasture. The third year a crop of corn, potatoes or vegetables is grown, and the following year small cereal grain and clover. The clover may thus be made to furnish nitrogen indefinitely for the other crops, but in some instances it may be necessary to add phosphoric acid and potash. =Preparing the Soil.=--Clovers are usually sown with a nurse crop. The exceptions are crimson clover, and in many instances alfalfa. When thus grown, the preparation of soil for the nurse crop will usually suffice for the clovers also. But there may be instances in which it would be proper to give more attention to cleaning and pulverizing the soil to properly fit it for receiving the clover seed. The leading essentials in a seed-bed for clover are fineness, cleanness, moistness and firmness. Ordinarily black loam soils, sandy loam soils, sandy soils, humus soils and the volcanic ash soils of the West are made sufficiently fine without great labor. Clay soils may call for the free use of the harrow and roller used in some sort of alternation before they are sufficiently pulverized. Excessive fineness in pulverization of these soils is also to be guarded against in rainy climates, lest they run together, but this condition is present far less frequently than the opposite. Cleanness can usually be secured when clovers follow cultivated crops by the labor given to these when the land is not plowed in preparing it for the clovers. In other instances the longer the land is plowed before putting in the seed and the more frequently the surface is stirred during the growing part of the season, the cleaner will the seed-bed be. In the spring the land is usually sufficiently moist for receiving the seed. In the autumn moisture is frequently deficient. Stirring the surface of the soil occasionally with the harrow will materially increase the moisture content in the soil near the surface, even in the absence of rain. As crimson clover is usually sown in the late summer and alfalfa is frequently sown in the autumn, it may sometimes be necessary to give much attention to securing sufficient moisture to insure germination in the seed. When clovers are sown in the spring on land which is also growing a winter crop, no preparation is necessary in preparing the land for receiving the seed. On some soils the ground becomes sufficiently honeycombed through the agency of water and frost to put it in a fine condition for receiving the seed. When this condition is not present, the seed will usually grow if sown amid the grain and covered with the harrow.