Green manure is a type of organic manure used for increasing soil fertility.
Green manuring is a process of ploughing or burying the undecomposed green plants into the soil to increase the fertility of the soil. Green manure is a plant material that is incorporated into the soil while it is green or after it reached maturity to supply nutrients like nitrogen to the standing crop. Green manuring is widely practiced in the states of AP, Karnataka, Punjab.
Green manuring contributes to about 40-80% of nitrogen per hectare.
Characteristics of Green manure
1.They have tolerance to adverse climatic conditions.
2. They have high seed production and longer seed viability.
3. They show resistance to pests and diseases.
4. They have high nutrient accumulation ability.
Types of Green manuring
Green manuring is of two types. They are
• Green manuring insitu- The green manure plants are grown and buried in the same field as the one to be manured.
Examples: Sunhemp (Crotalaria juncea), Dhiancha (Sesbania aculeata)
• Green leaf manuring- Green leaf manures refer to collecting of twigs.
Leaves from shrubs, trees from wastelands or nearby forests and incorporating them into the soil.
Examples: Glyricida (Glyricidia maculata), Karanja (Pongamia pinnata)
1.As green manure helps to increase the fertility of the soil it also increases the water holding capacity of the soil and decreases the soil erosion and run-off.
2.Green manures increase the availability of the nutrients NPK to the soil and also increase the soil structure and soil tilth.
3. They help to promote the yield from 15-20% more when compared to non- green manuring fields.
There may be some limitations like heavy labour requirement and the loss of one crop as green manure crops are grown in the same field. But this green manuring is of great help to the farmers as the soil in India are deficient of Nitrogen and phosphorous. This green manure along with the fertilizers help to restore the soil health.