When to plow Down.--Excellent farmers differ regarding the relative efficiencies of manure plowed down and that mixed with the top soil. Both classes may be right for their individual instances. The plowing down of manure helps to deepen the soil, and that always is desirable. It causes plants to root deeply, and that is a distinct benefit in a drouthy season, and always desirable. When a soil is in such tilth that the breaking-plow always brings fertile soil to the surface, the plowing down of manure gives excellent results, though it should be permitted to leach at the surface for a few weeks before being turned under. When land is being prepared for a seeding to grass or clover, the supply of manure should not be plowed down wherever the breaking-plow brings soil to the surface that is deficient in humus. In the latter case the manure always should be used as a top-dressing, and should be evenly spread and well mixed with the surface soil. It is needed there far more than it can be needed farther down. The surface soil always should have a high content of organic matter. Heavy Applications.--When the farm supply of manure is small, applications should be light. The manure should not be the dependence for plant-food on a part of a field, or a single field of the farm, under such circumstances. It is more profitable to give a light dressing to a larger area. The manure is needed to make a fertilizing crop grow, and a very few tons per acre can assist greatly, when rightly used. The manure is needed to furnish bacteria to the soil, and a small amount per acre is useful for this purpose. Always there is temptation to use all the manure on a field convenient to the barn, and to concentrate it on a sufficiently small area to make a good yield sure. The loss to the farm in this method is heavy. The thin spots and the thin fields have first right to the manure as a top-dressing, and six tons per acre will bring larger returns per ton than twelve tons per acre. At the Pennsylvania experiment station the land receiving ten tons of manure per acre in the common four years' rotation of corn, oats, wheat, and mixed clover and grass gives added returns of $1.63 a ton, while an application of eight tons pays $1.85 a ton, and a six-ton application brings the value per ton up to $2.41. These applications are made twice in the four years.