Biological indicators for assessing the maturity of the vermicomposted products of citronella bagasse and paper mill sludge mixture

Abstract

Maturity of vermicomposted end products obtained from citronella bagasse (CB) and a mixture of citronella bagasse and paper mill sludge (CB + PMS) was determined employing the epigeic earthworm species Eisenia fetida. Two of the primary biological indicators—enzyme assay and germination index—were used for evaluation of vermicompost maturity. The enzyme assay includes the changes in dehydrogenase and urease activities in the final products. The test for germination index was performed on two economically important plant species Abelmoschus esculentus and Solanum melongena. The results revealed a significant increase in dehydrogenase and urease activities in the vermicompost samples over the raw materials and traditional compost. The enhancement was recorded 215.63–225.63% in dehydrogenase and 149.89–249.31% for urease in the end products obtained after 45 days of experimental trials. Further, the higher values of germination index in the vermicompost treatments as against the control confirm the suitability and stability of the vermicomposted final products.