Manure is organic matter used as organic fertilizer in agriculture. Manures contribute to the fertility of, the soil by adding organic matter and nutrients, such as nitrogen, that are trapped by bacteria in the soil. Higher organisms then feed on the fungi and bacteria in chain of life that comprises the soil food web. It is also a product obtained after decomposition of organic matter like cow-dung which replenishes the soil with essential elements and adds humus to the soil In the past, the term "manure" included inorganic fertilizers, but this usage is now very rare.

Compost:- Compost is the decomposed remnants of organic materials – usually of plant origin, but often including some animal dung or bedding.

Plant Manures:- Green manures are crops grown for the express purpose of plowing them in, thus increasing fertility through the incorporation of nutrients and organic matter into the soil. Leguminous plants such as clover are often used for this, as they fix nitrogen using Rhizobia bacteria in specialized nodes in the root structure.

Other types of plant matter used as manure include the contents of the rumens of slaughtered ruminants, spent hops(left over from brewing beer) and seaweed.

Organic Manures

1. What are organic manures?

Organic manures are natural products used by farmers to provide food (plant nutrients) for the crop plants. There are a number of organic manures like farmyard manure, green manures compost prepared from crop residues and other farm wastes, vermicompost, oil cakes, and biological wastes – animal bones, slaughter house refuse.

2. How are organic manures beneficial in the cultivation of crops?

Organic manures increase the organic matter in the soil. Organic matter in turn release the plant food in available from for the use of crops. However, organic manures should not be seen only as carries of plant food. These manures also enable a soil to hold more water and also help to improve the drainage in clay soils. They provide organic acids that help to dissolve soil nutrients and make them available for plants.

3. How are organic manures differing from fertilizers?

Organic manures have low nutrient content and therefore need to be applied in larger quantities. For example, to het 25 kg of NPK, one will need 600 to 2000 kg of organic manure whereas the same amount of NPK can be given by 50 kg of an NPK complex fertilizer.

The nutrient content of organic manures is highly variable from place to place, lot to lot and method of preparation. The composition of fertilizers is almost constant. For example, urea contains 46% N regardless of which factory makes it anywhere in the world.

4. How much of plant nutrients are provided by organic manures?

Just as different fertilizers contain different amount of plants nutrients organic manures are also not alike.

Average quality of farmyard manure provides 12 kg nutrients per ton and compost provides 40 kg per ton.

Most of the legume green manures provide 20 kg of nitrogen per ton.

Each ton of sorghum/rice/maize straw can be expected to add 26 kg of nutrients.

5. What is green manuring?

Green manuring is the practice of growing a short duration, succulent and leafy crop and ploughing the plants in the same field before they form seeds.

6. What is green leaf manuring?

Green leaf manuring refers to adding the loppings from legume plants or trees to a field and then incorporation them into the soil by ploughing.

7. What green manure crops are beneficial?

Sesbania, Crotalaria, Pillipesara, Cowpea etc are good for green manuring.

8. What are the popular green leaf manuring plants?

Glyricidia, Pongamia, Leucina, are common green leaf manuring plants.

9. What is compost?

Compost is well decomposed organic wastes like plant residues, animal dung, and urine earth from cattle sheds, waste fodder etc.

10. How good compost is prepared?

Compost making is the process of decomposing organic wastes designated area of land. Site for compost making is selected should be at a high level of water should not pond during monsoon season. Length may be of any convenient size.

The site can be filled up sufficient organic wastes are available. Otherwise a temporary partition can be made in the site with open space stalks and the site can be filled up over time filling each partitioned area as and when the material is available for composting.