Biomanagement of sago bagasse with biogas plant slurry using an indigenous earthworms Perionyx ceylanensis Mich. and Lampito mauritii (Kinberg) for nutrients recovery

This paper reports the recycling of nutrients by vermicomposting of sago bagasse (SB) and biogas plant slurry (BPS) using indigenous earthworms Perionyx ceylanensis Mich. and Lampito mauritii (Kinberg). A total of twelve vermicomposting treatments were established for both worms and dynamics of physic-chemical parameters has been studied for 84 days (12 weeks). The waste mixture containing VT4, VT5 and VT6 for P. ceylanensis and VT10, VT11 and VT12 for L. mauritii had better fertilizer value among studied treatments. At the end of experiment (after 84 day), vermicomposts showed significant decrease in pH and total organic C but increase in total Kjeldhal N, total P and total K, Ca, Mg and Na contents for both worms. The C: N ratio of final vermicomposts also reduced to 11.4±0.19 - 22.6±0.52 for P. ceylanensis and 14.4±0.29 – 26.5±0.41 for L. mauritii from 63.4±5.2 – 87.5±4.5 in different vermicomposting treatments. The results revealed that SB could be converted into good quality fertilizer by vermicomposting if mixed in proper ratio (up to 60%) with BPS. Among the two species of worms, P. ceylanensis exhibits better nutrients recovery rate than L. mauritii