Effects of microbial inoculants on soil microbial communities and enhancement of tomato yield

Tomato (Lycopersicon esculentum) is one of the most widely cultivated vegetables and is rich in various nutrients. However, in facility production, the excessive application of chemical fertilizers has led to increasingly prominent problems such as soil nutrient imbalance, compaction, and salinization. These issues severely affect tomato yield and quality, becoming critical constraints to its sustainable development. This study investigated the effects of microbial inoculant application on soil conditions and tomato yield, aiming to provide both theoretical support and practical guidance for green tomato production in greenhouse systems. The group using conventional fertilization without microbial inoculants as the control, and microbial inoculants treatments were applied at the tomato transplanting stage to analyze their effects on soil physicochemical properties, microbial community structure, and tomato yield. The results showed that microbial inoculant application improved soil physicochemical properties, increased the relative abundance of beneficial bacterial genera such as Actinobacteria and Bacillus, and reduced the diversity and richness of fungal communities, including a decrease in the abundance of Fusarium in the soil. These changes promoted plant growth and significantly enhanced both the yield and quality of tomatoes. Specifically, average fruit weight increased by 10.58 %, sugar content rose by 25 %, palatability improved, storage time was extended by 20 days, and yield increased by 11.82 %.