Assessment of the Impact of Co-Applicationof Spent Mushroom Substrate-Based Bio-OrganicFertilizer and Compound Fertilizer on PassionFruit, Rhizosphere Soil, and Microbiota

This study investigated the effects of co-application of spent mushroom substrate (SMS) -based bio-organic fertilizer and compound fertilizer on passion fruit, soil properties, and rhizosphere microorganisms.The results demonstrated that the co-application significantly increased the total nutrients (17.73-81.21%)and available nutrients (25.09-102.80%) in the soil compared to the control group.The soil pH decreased by 0.23-0.71,and the soil organic matter content increased by 1.29-32.77%.Regarding microbial diversity, the application of SMS -based bio-organic fertilizer enhanced the abundance of beneficial microorganisms, reduced the disease incidence, and enhanced the crop's resistance to heavy metals.Regarding yield, the co-application treatment group achieved the highest passion fruit yield of 1.27 kg/plant, which was significantly higher than the control treatment (0.42 kg/plant).Fruit quality indicators, including soluble solids, acidity, and sugar-acid ratio, were also significantly improved.Based on the integrated results of soil properties, microorganism diversity, and yield performance, it is recommended to apply 2 kg/plant of SMS -based bio-organic fertilizer as a base and 8 g/plant of compound fertilizer as top dressing in passion fruit cultivation to enhance soil quality and optimize both yield and quality.