Effects of Combined Application of Vermicompost and Mineral Fertilizers on Melon Quality and Soil Environmental Quality

In the context of sustainable agriculture and environmental restoration, this study explores the potential of combining vermicompost with mineral fertilizers to optimize crop production while reducing the environmental footprint of synthetic fertilizer use. A greenhouse experiment was conducted to compare four nitrogen treatments: no nitrogen (CK), 100% mineral fertilizers (T1), 50% mineral fertilizers + 50% vermicompost (T2), and 100% vermicompost (T3). The experiment focused on key parameters, including melon yield, fruit quality (soluble sugars, soluble solids, and vitamin C), and soil environmental health. The results indicate that the T2 treatment, which integrates vermicompost, produced the most favorable outcomes: a 28.9% increase in soluble sugar content, improved flavor, and 3–7 days earlier pollination/harvest compared to CK. Soil organic matter in the T2 treatment was 2.6 times higher than CK, with significant improvements in microbial diversity and enzyme activity, enhancing soil fertility. Correlation analysis revealed strong associations between melon quality, soil health, and microbial dynamics. This integrated fertilization strategy not only enhances melon productivity but also promotes soil ecosystem sustainability, aligning with ecological restoration principles. These findings offer practical recommendations for reducing reliance on mineral fertilizers in melon farming systems while improving soil and environmental quality.