Manure

Manure, plant or animal wastes used as fertilizer. Rich in humus (decaying organic matter), manure releases many important nutrients into the soil. However, manure is deficient in three important nutrients: nitrogen, phosphorus, and potassium. A commercial fertilizer has about 20 times as much nitrogen, phosphorus, and potassium as an equally massive amount of manure. For this reason, manure is often used in conjunction with other fertilizers. Manure also helps to loosen soil and retain water.