Sustainable treatment and nutrient recovery from leafy waste through vermicomposting.

The present investigation was carried out to evaluate the vermicomposting potential of two cruciferous vegetables' residual biomasses under laboratory conditions. Cabbage and cauliflower residual biomasses were spiked with 60% cow dung and vermicomposted for 90 days. The results showed a decrease in pH (5.3-9.8%), Total Organic Carbon (36.7-42.8%); increase in Electrical Conductivity (33-99.4%) and ash content (144.7-187.8%) after vermicomposting. Significant reduction in C:N ratio (49.5-76.4%) and C:P ratio (62.8-66.04%), increase in Total Kjeldahl Nitrogen (49.3-85.3%), Total Available Phosphorus (68.2-98.1%), Total Potassium (91.8-120.3%) were observed. FT-IR spectra of the vermicomposts had lesser band heights and peak intensities than raw materials. This evidenced decomposition of organic compounds and vermicompost stability. Germination Index values was calculated to determine the phytotoxicity level. Earthworms' growth and prolificacy was evaluated in terms of biomass gain, cocoons production and worm growth rate. Finally, it was inferred that cruciferous vegetables' biomass can be used for vermicomposting. The cauliflower residual biomass has shown better decomposition efficiency than cabbage residual biomass.

Management of banana crop waste biomass using vermicomposting technology.

This study reports the vermicomposting of banana crop waste biomass by Eisenia fetida. Cow dung has been used as bulking agent in this study. The experiment was conducted in six vermireactors containing different ratios of banana leaf waste biomass (BL) and cow dung (CD) for 105 days. Earthworm activity significantly reduced pH, TOC, C:N and C:P ratio of the wastes. Whereas macronutrients and micronutrients content increased after vermicomposting. TOC content of wastes reduced by 40-64% and C:N ratio of the vermicomposts was in the range of 8.9-24.3. The benefit ratio for heavy metals (Cu, Fe, Zn, Cd, Pb, Mn and Cr) was in the range of 0.23-3.44. The results indicated that the growth and fecundity of the earthworms was best in the vermireactors having 20-40% BL. Finally, it was concluded that vermicomposting can be included in the overall scheme of banana crop waste management.