Fertilizer for Grass.--A fertile soil will make a good sod. A thinner soil should have a liberal dressing of complete fertilizer at seeding time, and the formula that has been suggested is excellent for this purpose. If a succession of timothy hay crops is desired, the problem of maintaining fertility is wholly changed. The nitrogen supplied by the clover is soon exhausted, and the timothy sod must be kept thick and heavy until broken, or the soil will not have its supply of organic matter maintained. Nitrogen must be supplied freely, and phosphoric acid and potash must likewise be given the soil. The draft upon the soil is heavy, and at the same time the effort should be to have a sod to be broken for corn that will produce a big crop without the use of any fertilizer. The grass is the natural crop to receive the plant-food because its roots fill the ground, and the corn should get its food from the rotting sod, when broken. Station tests have shown that a sod can be caused to increase in productiveness for several years by means of annual applications of the right combinations of plant-food in the early spring. A mixture of 150 pounds of nitrate of soda, 150 pounds of acid phosphate, and 50 pounds of muriate of potash is excellent. This gives nearly the same quantity each of nitrogen, phosphoric acid, and potash, and is near a 7-7-7 fertilizer. The only material change in relative amounts of plant-food constituents, when compared with a 3-10-6 and 3-8-10 fertilizer, is in the increase of nitrogen, due to the heavy drafts made by continuous mowings of timothy. This fertilizer should be used as soon as any green appears in the grass field in the spring after the year of clover harvest. The large amount of nitrogen makes this an unprofitable fertilizer for clover, and its use is not advised until the spring of the year in which timothy will be harvested. All the Nitrogen from Clover.--The Pennsylvania station has shown in a test of thirty years that when good clover is grown in a four-years' rotation of corn, oats, wheat, and clover, the fertility of the naturally good clay loam soil may be maintained, and even slightly increased, without the use of any manure or purchased nitrogen. Phosphoric acid and potash have been applied, and the clover hay crop has been taken off the land. This result has been possible only by means of good clover sods. If there had been no applications of phosphoric acid and potash, the clover would have failed to maintain fertility, as is proved by other plats in this experiment. No one should continue to depend upon such a scheme of keeping land fertile whenever he finds that the clover is not thriving.