The rapid increase in the volume of waste is one aspect of the environment crisis, accompanying global development. Earthworms play an important role in the decomposition of organic matter and soil metabolism through feeding, fragmentation, aeration, turnover and dispersion. The type of substrates used and species of earthworms introduced plays a significant role in plant growth and yield. The waste to be stabilized should support an adequate biomass needed for effective processing. In the present study the vermicompost produced from banana as a substrate did not show a significant increase in NPK content from that of the control. On the other hand poultry waste and vegetable waste with goat dung showed significant increase in the NPK content. The enhancement of the vermicompost was probably due to mineralization of the organic matter containing proteins and conversion of ammonium nitrogen into nitrite. Mineralization and consequent mobilization of phosphorous by enhanced bacterial and phosphatase activities during vermicomposting leads to increase in Phosphorus. The earthworm processed waste materials contain high concentration of exchangeable potassium, due to enhanced microbial activity during the vermicomposting process, which accordingly enhanced the rate of mineralization. Vermicompost tends to hold more nutrients over larger periods without adverse effects on the environment.
Part of the book: Organic Fertilizers