COMPOSTS are a kind of manure (q.v.), consisting of mixtures of substances adapted to the fertilization of the soil, which being allowed to ferment, and undergo chemical changes for a considerable time in heaps, become more valuable than they were at first, or ever could have been if applied separately. C. were formerly made of farm-yard manure, and earth or lime in addition. Road-scrapings, peat-moss, leaves, and clear ings of ditches, also formed materials for the purpose. By allowing these to lie in heaps for G months, of from 3 to 4 ft. in depth, food was prepared for plants. The mass was usually applied to the turnip crop, and when artificial manures were unknown, consid erable benefit arose from such dressings. The 'use of guano and other light manures has superseded in a great measure the necessity of this laborious process, and C. for the turnips or barley crops are now little used. The wonderful effects that have resulted from the application of small doses of nitrogen and phosphoric acid, have impressed farm ers in general with the truth, that the most energetic elements bear a small proportion in weight to the whole mass of farm-yard dung or C., and that the mixing of manures
in heaps with earth does not so much add to its virtues as to repay the labor expended in the process. More care is now rightly bestowed in preserving manure from washings by rain. C. formed of leaves, ditch-scourings, road-scrapings, or any earthy matter con taining a large percentage of vegetable matter, with the addition of lime, may still be used with benefit for pastures that are deteriorating, or where the soil is stiff. Where moss prevails, lime should enter largely as a component. On the other hand, where the soil is of a strong and clayey nature, earthy substances containing vegetable matter in larger proportions should be used. Vegetable matter has the effect of imparting a soft ness to the surface, that is particularly conducive to the free growth of pastures. Com post made of turf, leaves, earth, and bone-dust is used with great benefit by gardeners for vines and fruit trees which are injured by too concentrated manures.