In general farming the best practice is to apply manure to the land as soon as possible after it is produced. This may also be the best policy in certain lines of vegetable farming; as, for example, grass land to be planted in early cabbage and early sweet corn might well receive dressings of fresh manures, any time after hay harvest of the previous season. In field trucking a very general and commendable practice is to apply fresh manures at any time, provided all conditions are favorable to such applications. The probabilities are that yields will be better than if an attempt is made to store the manure and apply when well decomposed. It is a well-known fact, however, among market gardeners that fresh stable manures are not suitable for intensive operations in market gardening, because they are not quick enough in their action and their coarse texture prevents thorough incorporation with the soil particles. Again, fresh manures are likely to cause a rank growth of certain crops, such as tomato, eggplant, pepper, melon and cucumber, at the sacrifice of fruit. With root crops, like radish, turnip, beet, carrot, parsnip and salsify, fresh manures not only cause excessive top growth, but also prevent the proper root development. It is, therefore, generally conceded that rotten manure is indispensable in all intensive lines of vegetable gardening. 86. Composting manures.—On almost every place devoted to market gardening there is a compost pile. Although it is called the compost pile, it seldom contains much material in addition to horse manure. This does not have reference to the sod and general compost heaps near most greenhouse establishments. The manure compost pile is essential because (1) manure is hauled the year round and the land is generally occupied with growing crops when it is impossible to apply directly to the soil; (2) fresh manure is too coarse to apply in large amounts immediately before planting, because it cannot be incorporated thoroughly with the soil; (3) fresh manure induces a rank growth of stem and leaf at the expense of a good crop; (4) composting destroys troublesome weed seeds.
Valuable data upon this subject have been published by the Maryland station. The results obtained show that:
(1) when manure is allowed to ferment in piles for six months no danger of distributing weed seeds is incurred;
(2) when manure is allowed to remain in piles, undergoing partial fermentation, little danger of distribution is incurred.
Although composting is essential, it should be avoided as much as possible, for decomposition cannot be controlled without some loss of plant food. It also requires a large additional expenditure of labor in the extra handling.
In the management of compost heaps the gardener should see that leaching and fire-fanging are controlled and that the finest texture is secured. To accomplish these ends it is customary to stack in rather compact, flat piles not less than 4 feet deep, and covering as much area as may be necessary. The piles are so deep that there can be no leaching if they are built with perpendicular sides. They must be watered with a hose often and freely enough to prevent fire-fanging. To improve the texture, the piles are turned from one to three times at convenient intervals. About six months are required to secure the proper decomposition. A manure shredder is used by some Boston gardeners. This powerful machine, operated by an engine, is placed alongside of the compost pile and the manure is shredded before applying in the field. The shredder is provided with a tongue, so it may be shifted with a team whenever necessary.