Precomposting and green manure amendment for effective vermitransformation of hazardous coir industrial waste into enriched vermicompost

Abstract

Vermitransformation of coir pith (CP) into enriched vermifertilizer has been achieved by amending a green-manure plant, Sesbania sesban (SS) for the first time, and cow dung (CD) in five different combinations: T1_(1:0:1), T2_(4:3:3), T3_(5:3:2), T4_(5:4:1) and T5_(1:1:0). The substrates were 28 days precomposted with Pleurotus sajor-caju followed by 50 days vermicomposting with Eisenia fetida and Eudrilus eugeniae. Results showed a significant reduction in cellulose, lignin, organic carbon, C/N ratio, C/P ratio and an increase in plant nutrients compared to control. The fertilization index and efficiency of nutrient recovery rate were higher in SS and CD amended CP vermicompost, with a maximum in T2_(4:3:3) for E. fetida and T3_(5:3:2) for E. eugeniae. The activity of dehydrogenase, urease and cellulase, and phytotoxicity assays further revealed vermicompost stability. The study concludes that T2_(4:3:3) and T3_(5:3:2) combinations respectively for E. fetida and E. eugeniae is suitable for vermitransformation of CP into enriched vermicompost.

Keywords: Coir pith; Enriched vermicompost; Green manure; Nutrient recovery; Phytotoxicity.