1Ministry of Agriculture, Fisheries and Food, Great Westminster House, Horseferry Road, London SW1P 2AE, U. K.
Tóm tắt
Farm animal excreta may fall directly on grazed crops or be collected from housed animals as semi-liquid slurry or more solid manure. Estimates are given of the total amounts of N in animal excreta in the U. K. and in the various forms in which it may be collected from housed animals. The factors affecting the losses of N from stored manures and the availability to crops of the N content of manures are reviewed. The optimum use of the N content of manures as a crop nutrient is discussed in relation to practical farming problems including the costs to farmers of storing manures and slurries, the difficulties of applying these materials to land at particular times of the year, and the risks of causing pollution of water.
