Effects of Different Substrate Ratios on Bacterial Community Structure and Diversity in the Rhizosphere of the Tomato

Although peanut shells represent an abundant agricultural waste, their high-value utilization potential as a horticultural substrate has not been fully recognized. Meanwhile, horticultural crops such as tomatoes are in urgent demand for high-quality and innovative cultivation substrates. This study investigated the effects of different ratios of peanut shell–substrate on tomato yield and rhizosphere bacterial community structure, aiming to provide a theoretical basis for the utilization of agricultural waste and the development of novel growth substrates for tomato cultivation. Results showed that peanut shell–substrate improved tomato yield and quality, and enhanced soil urease, sucrase, and catalase activities. High-throughput 16S rRNA gene sequencing revealed significant differences in rhizosphere bacterial alpha diversity between peanut shell substrates and the control. Proteobacteria, Acidobacteria, and Actinobacteriota were the dominant phyla, while unclassified genera, Devosia A₅01803 and Bauldia, were identified as the core genera at the genus level. In conclusion, peanut shell substrates enriched dominant functional bacterial genera and enhanced the ecological functions of the substrate.