What are manures? Give its classification.

Hint: Nutrients are required by the soil for better productivity and fertility respectively. The soil rich in nutrients is very fertile. Plants take up nutrients from the soil which in turn are included in the food.

Complete step by step answer:
Manures are the kind of different kinds of organic wastes that improve soil fertility. They generally are rich in moisture and contain different types of good amounts of nutrients required by the soil. The soil improves its fertility in such a way that when manures are added the humus content is increased in the soil making it more suitable for agriculture.

Manures can be classified into three basic types and are used accordingly, they can be;
(a) Animal Manure: includes the basic animal dungs (basically i.e., cow dungs, etc.). It also includes animal wastes used for composting.
(b) Human Manure: includes basic human waste, such as; human excreta i.e. urine or feces.
(c) Green Manure: includes basic plant wastes gathered from unused or dead plants or its parts.

Additional Information:
- Crops that are sown in an agricultural field require adequate quality and quantity of moisture and humus.
- Humus is retained through the addition of manures.
- Humus is the dead plant or its parts used for increasing soil fertility.
- A barren land could be made fertile through the addition of different kinds of manures.
- Manures are used in complement with the mutual use of fertilizers.
- Nitrogen is the basic nutrient required by the plants for their growth.

Note: Manures are used as a core ingredient for maintaining up soil fertility and increasing production through different agricultural practices.