Optimizing vermicompost-soil ratios for synergistic enhancement of Allium fistulosum growth dynamics and phytochemical quality

To determine the optimal vermicompost application ratio in vegetable cultivation, this study focused on <i>Allium fistulosum</i> (variety NC89) and conducted a pot experiment with five treatments, using vermicompost-to-soil mass ratios of 0% (control), 25%, 50%, 75%, and 100%. Growth indicators and quality parameters were measured, and the vermicompost effect was analyzed based on morphological characteristics. Results showed that under the 50% treatment, the vitamin C and soluble sugar contents of <i>A. fistulosum</i> were significantly higher than those under other treatments. The biological yield and fresh weight were relatively high, and growth indicators such as root length and plant height were well - coordinated. The number of tillers was significantly greater, with dark green leaves and compact texture. The 75% treatment had the lowest nitrate content, but its growth indicators were slightly inferior to those under the 50% treatment. A comprehensive analysis indicated that a 50% vermicompost-to-soil ratio could synergistically improve <i>A. fistulosum</i> yield and quality by enhancing soil aeration and balancing nutrient supply. This study provides a theoretical basis and technical reference for rational vermicompost application in protected vegetable cultivation.