Vermicomposting of Sugarcane Trash and Leaf Litter in Combination with Pressmud Using the Earthworm, Perionyx ceylanensis

In the present study, initial vermicomposting trials were conducted for 100 days using leaf litters of Polyalthia longifolia (LPL) and sugarcane trash (SCT), each in combination with pressmud (PM) (i.e., 0:100, 25:75, 50:50, 75:25 and 100:0) by inoculating an epigeic earthworm, Perionyx ceylanensis. Based on C/N ratio, worm biomass and numbers recorded in vermicomposting trials, organic substrates + PM in 50:50 (1:1) proportion was selected for 60 days vermiconversion studies. Nutrient and microbiological changes during vermicomposting was studied with a special focus on the enzymes in the gut and vermicasts of P. ceylanensis. The NPK contents in worm worked substrates were higher than worm unworked LPL + PM and SCT + PM substrates. The C/N ratio of vermicompost showed decrease over compost (worm-unworked) and percent decrease observed was significant (P < 0.001). The total microbial population (bacteria, fungi and actinomycetes) present at the end of experiment (60 day) was significantly higher (P < 0.05) than the microbial population present at the start of the experiment in both the substrates. Amylase, cellulase, invertase, phosphatase and protease in fresh vermicasts of P. ceylanensis showed higher activities when reared in LPL + PM substrate. The activities of the enzymes cellulase, invertase and protease in vermicasts of P. ceylanensis were significantly higher in LPL + PM. The activity of these enzymes while ageing showed an increase up to 15-20 days and then declined. In the vermicasts recovered from LPL + PM and SCT + PM (1:1), cellulase showed highest activity at the end of 30 days. The present study reveals that the clitellate P. ceylanensis exhibit higher activity of amylase, cellulase, invertase, phosphatase and protease. _____________________________________________________________________________________________________________