Middle English manouren, from Anglo-French mainouverer, meinourer to till (land), construct, create, from Medieval Latin manu operare to perform manual labor, from Latin manu by hand + operari to work — more at operate
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 fertilizers and therefore must be applied in much greater quantities, it is rich in organic matter, or 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 alsogreen manure.