Integrated use of municipal solid waste amendment with poultry manure for enhancement of soil nutrient status and productivity of spinach (Spinacea oleracea L.) in Inceptisol

Soil fertility decline caused by the depletion of soil organic matter is a critical global challenge. Organic amendments such as municipal solid waste (MSW) compost and poultry manure represent promising alternatives to chemical fertilizers, providing both nutrient recycling and sustainable waste management solutions. A pot experiment was conducted at Banaras Hindu University, India, to evaluate the effects of MSW compost and poultry manure, applied individually and in combination, on the growth, yield, and nutrient composition of spinach ( Spinacea oleracea L.). Treatments included MSW compost at 20, 30, and 40 t ha − 1 , alone and supplemented with poultry manure at 5 t ha − 1 . Results demonstrated significant improvements in plant growth parameters, leaf yield, and nutrient accumulation compared with the control. The combined application of MSW compost and poultry manure, particularly at 40 + 5 t ha − 1 , respectively, produced the highest yields (17.49 t ha − 1 ) and nutrient uptake, representing 62.5% yield enhancement over control. Plant height increased by 30.8%, leaf area index by 51.2%, and chlorophyll content by 10.9% with integrated treatments. Soil organic carbon, available macro and micronutrients also increased significantly under integrated treatments, indicating enhanced fertility. The heavy metals accumulation in post-harvest indicates their presence well under the permissible limit. The study highlights the synergistic benefits of integrating MSW compost with poultry manure and suggests a sustainable pathway for waste utilization and soil fertility improvement in vegetable production systems.