Organic material that is used to fertilize land, usually consisting of the feces and urine of domestic livestock , with or without litter such as straw, hay, or bedding.
Some countries also use human excrement ("night soil"). Though livestock manure is less rich in nitrogen, phosphorus, and potash than synthetic humus , and thus improves the capacity of the soil to absorb and store water, thereby preventing erosion. Because manure must be carefully stored and spread in order to derive the most benefit, some farmers decline to expend the necessary time and effort. Manufactured chemical fertilizers, though more concentrated and efficient, are also more costly and more likely to cause excess runoff and pollution. See also green manure .