6.2. Effect on Microorganisms:
The casts contain highest population of microorganisms compared to other surrounding soil. Mycorrihizal colonization in plant root system is enhanced in soils containing earthworms. There is also some evidence that earthworms feed on pathogenic soil nematodes and nematode infection is reduced in plots where earthworms are cultured.

6.3. Castings:
Food after passing through the alimentary canal of the worms emerges as a compact concentrated mass termed castings. An earthworm cast is rich in microorganisms, organic minerals and organic matter in a form available to plants.

6.4. Effect of earthworms on soil structure:
Earthworms affect the soil structure by ingesting the soil, partially breaking down organic matter, mixing these factions and ejecting the material as surface or subsurface casts. A comparatively new angle is the claim that certain beneficial chemicals are released from the bodies of earthworms, which increase crop yields.

6.5 Mineralization of nutrients:
The ratio of carbon to nitrogen in the compost is very important ( Edward and Lofty, 1977). Plants can not assimilate mineral nitrogen unless this ratio is of the order of 10:1 or lower. The C/N ratio of fresh waste or leaf litter is much higher than this critical point. During the process of decomposition the C : N ratio of the material decreases progressively. Earthworms feeding on waste gradually lower its C/N ratio as they break down the material during their metabolism. The lowering of C/N ratio is achieved mainly through combustion of carbon. Earthworms consume plenty of plant organic matter that contain large quantities of nitrogen and much of this is returned to soil. In this way they increase the quantity of mineralized nitrogen and much of this is returned to soil . In this way they increase the quantity of mineralized nitrogen and much of this is returned to soil. In this way they increase the quantity of mineralized nitrogen and make it available for plant growth.

6.6. Continuous use of vermicompost gives resistance to plants against many pest and diseases, thereby resulting in lower expenditure on chemical pesticides. By reducing/eliminating chemical environmental pollution by the chemical pesticides could be effectively brought down.

6.7. Earthworms produce various enzymes, hormones vitamins and antibiotics which helps the plant to grow faster.

6.8. It increases the availability of nutrients to the plant due to the presence of high humus content. It also enhances the uptake of chemical fertilizers. It is reported that continuous vermicompost application helps to boost productivity by 10-20 per cent even in areas with lower organic nutrient inputs.

6.9. It is also reported to enhance the quality of end products Organoleptic factors and keeping quality.

6.10. Following are the advantages due to vermicompost application in plantation.

	Better seed germination in Cardamom and Grevillea
	Increase root growth in the nurseries (tea, coffee and cardamom).Because of this the nursery period can be brought down considerably
	Abundant tiller production in cardamom both in nursery and field
	Vermicompost in the planting pits induces profuse root development, which helps the plants to with stand drought stress in summer
	Improvement in cardamom capsules
	Low incidence of slow wilt and quick wilt in pepper
	Significant yield increase is also obtained in tea event at reduced level of inorganic fertilizer application