Function of organic manure

1. They provide essential elements to the plant and have the direct effect on plant growth like any other commercial fertilizers. They contain very small quantity of plant nutrients, therefore large quantity of them need to be applied per unit area to obtain better yield.
2. They supply organic matter to the soil and hence improve the physical properties of the soil like soil structure, aeration, water holding capacity, soil temperature, bulk density etc.
3. They provide food for soil micro-organisms and stimulate them, which are responsible for various activities in the soil.
4. Organic manure increases the biochemical process like cation and anion exchange capacity and provides a buffering action in soil reaction and also influences the solubility of soil minerals as well as mineral nutrients in soil.
5. They prevent loss of nutrients by leaching or erosion.
6. They also regulate the thermal regimes of the soil.
7. Carbon dioxide released during organic matter decomposition acts CO2 as fertilizer for plant roots.
8. Plant parasitic nematodes and fungi are controlled to some extent by altering the balance of microorganisms in the soil.