Production of nutrient-enriched vermicompost from aquatic macrophytes supplemented with egg shell, bone meal, banana peel, and tea waste: Assessment of nutrient changes, phytotoxicity, and earthworm biodynamics

Abstract

Vermicompost is an organic fertilizer rich in nutrients, beneficial microbes, and plant growth hormones that not only enhances the growth of crops but also contributes to the improvement of the physicochemical and biological properties of the soil. However, its lower nutrient content makes it less preferable among farmers and limits its applicability. The present study, evidently the first of its kind, was investigated to enrich the nutrient content of vermicompost by supplementing the macrophyte biomass with cow manure and organic nutrient supplements (egg shell, bone meal, banana peel, and tea waste). Results showed an enhanced TKN (2.87%), TP (0.86%), TK (3.74%) and other nutrients in vermicompost amended with cow manure and nutrient supplements. Highest biomass gain (710-782 mg), growth rate (11.83-13.04 mg), and reproduction rate (3.34-3.75 cocoons per worm) was also observed in T2 and T3, indicating that amending bulking agent and nutrient supplements not only enhance the nutrient content of the final product but also improve overall earthworm activity. The stability and maturity of vermicompost, as indicated by C/N (< 20) and GI (> 80), indicates that vermicompost obtained is suitable for agricultural applications. It is concluded that amendment of cow manure and organic nutrient supplements results in producing mature and nutrient enriched vermicompost suitable for sustainable agricultural production.