Climate resilient bio-management of agricultural waste through vermicomposting to produce organic fertilizer

Abstract

Sustainable management of agricultural waste and declining soil fertility remain major challenges for agriculture, particularly under increasing climate-induced stress. This study evaluated the effectiveness of vermicomposting using Eisenia fetida and molasses to convert combinations of cow dung, poultry waste, and vegetable waste into nutrient-rich organic fertilizer. A Completely Randomized Design (CRD) was used for decomposition assessment, while a Randomized Complete Block Design (RCBD) evaluated effects on soil health, crop yield, and drought resilience in lettuce. Results showed that vermicomposting significantly accelerated decomposition compared to conventional composting. Earthworm activity enhanced microbial processes, waste fragmentation, and nutrient mineralization, while mixed substrates produced synergistic effects that improved nutrient availability. Vermicompost treatments demonstrated superior agronomic quality, indicating advanced maturity and reduced phytotoxicity. Nutrient analysis revealed increased macronutrient concentrations, particularly in mixed waste treatments, confirming enhanced mineralization and bioavailability. Application of vermicompost improved soil fertility, structure, and microbial activity, creating favorable conditions for plant growth. Lettuce grown in vermicompost-amended soils exhibited higher fresh and dry biomass, improved yield, and greater drought resilience. These improvements were linked to enhanced soil moisture retention, improved root development, and slow-release nutrient availability. Additionally, molasses served as an energy source for microbial communities, accelerating decomposition and enhancing humification, resulting in stable, carbon-rich compost. Improved soil aggregation and water retention further supported plant performance under water stress, while enhanced root proliferation increased nutrient uptake efficiency and drought tolerance.These findings demonstrate that vermicomposting with Eisenia fetida, especially using mixed organic wastes, is a low-cost, climate-smart, and biologically efficient strategy for sustainable agricultural waste management and soil improvement.