Define
1. Vermicompost
2. Green Manure
3. Biofertilizers.
1. Vermicompost:
It is a manure rich in pulverised organic matter and worm castings. Vermicompost is formed by the activity of earth worms on organic remains.
2. Green Manure:
It is manure formed inside soil from young green crop plants ploughed hack into soil. The green manure crops are generally quick growing legume crops which are mulched by ploughing them back into field in tender stage (about $6-8$ weeks) only, generally at the time of flowering. These crops are completely decomposed in about 1-2 months when the next crop can be sown.
3. Biofertilizers:
Living organisms like nitrogen fixing bacteria, nitrogen fixing blue-green algae and mineral solubilising bacteria that supply nutrients to crop plants are called biofertilizers.