Manure is a partially decayed organic wastes that increase the soil fertility. They supply all essential elements required by crop plants. They also improve the physical conditions of soil by preventing erosion and leaching and increase the water holding capacity of the soil.

Manure are of two types 

(i) Green Manure and 

(ii) Farmyard Manure

(i) Green Manure : They are obtained by cultivating quick growing leguminous and non- leguminous crops. The crop is ploughed when the plants are about one foot height. The green manure crop supplies the organic as well as inorganic components to the soil. It also provides a protective action against erosion and leaching e.g. Dhaincha (Sesbania aculeata) cluster beans (Cymopsis tetragonoloba), sun-hemp (Crotolaria juncea), cowpea (Vigna sinensis) are some of leguminous crops commonly used as greeen manures.

(ii) Farmyard Manure: It is the most valuable decayed organic matter commonly applied to the soil. It is obtained by the partial decay of animal dung, farm refuse and crop residues. These materials are stored in heaps in a pit and kept moist. The manure becomes ready after 4-5 months. The manure is dark coloured, amorphous and rich in humus. Manure enriches the soil with organic substances and releases mineral elements in the soil. Residue of gobar gas plant is a kind of farmyard manure.