Vermiconversion of biowastes with low-to-high C/N ratio into value added vermicompost

Abstract

Seaweed (T1), sugarcane trash (T2), coir pith (T3) and vegetable waste (T4) with cowdung (1:1, w/w) were vermicomposted using Eudrilus eugeniae (50 days). The pH in vermicomposts showed a decrease while electrical conductivity showed increment. The organic matter content, organic carbon, lignin, cellulose, C/N and C/P ratios in vermicompost was significantly lower than compost. Total NPK contents of vermicompost were significantly elevated (P < 0.05) with 12.04–63.75%, 19.05–31.58% and 22.47–42.55%, respectively. The significantly higher growth rate of 1.41 and 7.74 mg/worm/day was observed in T1 on 10th and 50th day respectively, with 23.91 initial C/N ratio; while it was 0.85 and 4.81 mg/worm/day in T4 with 69.81 initial C/N ratio. A similar pattern was reflected in cocoon production, hatchling success and hatchling number/cocoon. Results revealed that vermicompost quality, worm growth, and reproduction depend on C/N ratio. The study suggests that amendment materials like cowdung are necessary to reduce C/N ratio for effective vermicomposting.