Impact of Fertilizer Applications on Growth and Yield of Leafy Vegetable Crops under Mixed Crop-Livestock Systems

Abstract

Fertilizer use plays a critical role in leafy vegetable productivity, but excessive reliance on chemical fertilizers can degrade soil health and reduce long-term sustainability. Mixed crop-livestock (MCL) systems, incorporating organic manure with or without reduced synthetic inputs, offer an integrated approach that enhances nutrient cycling and improves crop yield sustainably. In this study, three leafy vegetables—amaranthus (Amaranthus sp.), spinach (Spinacia oleracea), and lettuce (Lactuca sativa)—were grown under seven fertilizer treatments: control, urea, NPK, compost, farmyard manure (FYM), vermicompost, and integrated fertilizer management (50% urea + 50% compost). Growth parameters measured included fresh weight and number of leaves per plant. Results revealed that integrated treatment produced the highest fresh weight values across crops (210 g/plant in lettuce, 175 g/plant in spinach, and 165 g/plant in amaranthus), representing yield increases of 85–120% over control treatments. Vermicompost ranked second, achieving 15–25% higher fresh weight than sole chemical fertilizers. Leaf number was enhanced by 30–45% under vermicompost and integrated treatments compared to urea or NPK alone. Chemical fertilizers improved fresh weight but were less effective in enhancing leaf number compared to organic amendments. These findings underscore the potential of integrated nutrient management for sustaining leafy vegetable production in MCL systems while maintaining soil health and reducing environmental impacts.