PRODUCTION OF VERMICOMPOST FROM AGRICULTURAL WASTES-A REVIEW.

A cris-cross review on vermicompost from agricultural wastes reveals that C-N ratio, pH, moisture content and temperature of the substrates are the most important parameters for proper vermicomposting as they determine the litter palatability in detrivorus earthworms. Feed material having C-N ratio less than 40 can be used successfully for vermicomposting. A temperature of 18 to 250C and moisture content of 40 to 60% were most congenial. Substrate treatment by bioinoculants and or addition of rock phosphate enriches the vermicompost through increase in the total nitrogen and available phosphorus and potassium content of vermicompost. Vermicompost prepared out of the mixture of crop residues amended with cow-dung in the ratio of 1:1 also exhibits higher nutrient content. Mixed culture of Eisenia foetida, Eudrilus eugeniae and Perionyx excavatus in vermicomposting shows higher multiplication rate of the worms. Cow-dung has widely been accepted as the best substrate provided its pH is below 9.5. Cereal and leguminous wastes, tree leaves and weeds are also found suitable while fresh poultry and pig manure and glyricidia stems are unsuitable. Vermicompost from obnoxious weeds like Eichhornia crassipes, Salvinia molesta, Lantana camara, Trapa sp. can be prepared with in 6 to 7 weeks with recovery of about 50 to 53%. Substrates containing 1 to 5% green leaves of leguminous trees can be suitably used for vermicomposting but poisonous plants or plants sprayed with insecticides are always fatal to the earthworms. Overall high rate of growth and reproduction of earthworms in the substrates are the best indicators of effective vermicomposting. Storage of vermicompost beyond 10 weeks decreases the microbial biomass, plant hormone concentration and enzyme activity. [ABSTRACT FROM AUTHOR]