a) Animal Manure
These are usually animal droppings or dung,urine and slaughter house wastes . Animal wastes provide the largest source of plant nutrients . Among animal or organic manure farmyard, manure (FYM) is most common and important source . FYM is more or less decomposed mixture of animal droppings, urine with the straw or other litter that is used in the yards to absorb the liquid portions and keep the animal lean; left over fodders, farm sweep and crop residues . Animal dung is the major component of FYM . One tonne of fresh manure supplies 227 kg organic matter , 4.5 kg nitrogen , 2.5 kg P2O5 and 4.5 kg K2O . b) Crop Residues
It include straws , husks , leaves , vegetable and fruit wastes , grass cuttings , weeds , etc . The major agricultural crops such as cotton , sugarcane , rice and wheat return about 8 to 45% roots , shoots , leaves etc . Their composition varies with the kind of materials and stage of plant growth . c) Compost
A manure derived from decomposed plant residues ( through the action of micro-organisms ) in soil . It is usually made by fermenting waste plant material ( e.g. , straw , grass , etc . ) in heaps usually in alternate layers with added lime , N and water . It is usually used in green houses. Types of compost .
i . Rural compost
Crop residues , stubbles , weeds , fallen leaves , leftover fodder and green manure , etc . , can be collected and stored in a heap or pit . ii . Urban compost
This is prepared from muncipal/industrial waste comprising mainly of town refuse and human exerets . d) Agro-Industrial wastes
Rice husk , leather flesh , fibre free strew , pitch , pulp , peels , press mud and molasses . e) Weeds
f) Night Soil ( human excretions )
g) Green Manure
A crop preferably legume...