Effects of reductive soil disinfestation combined with different types of organic materials on the microbial...

Reductive soil disinfestation (RSD) is an effective method to inhibit soilborne pathogens. However, it remains unclear how RSD combined with different types of organic materials affects the soil ecosystems of perennial plants. Pot experiments were conducted to investigate the effects of RSD incorporated with perilla (PF), alfalfa (MS), ethanol, and acetic acid on soil properties, enzyme activities, microbial communities and functions, and seedling growth. Results showed that RSD-related treatments improved soil properties and enzyme activities, changed microbial community composition and structure, enhanced microbial interactions and functions, and facilitated seedling growth. Compared with CK, RSD-related treatments increased soil pH, available nitrogen, and available potassium contents, sucrase and catalase activities, and decreased soil electric conductivity values. Meanwhile, RSD-related treatment also significantly reduced the relative abundance of Fusarium while increasing the relative abundance of Arthrobacter, Terrabacter, and Gemmatimonas. The reduction was more evident in PF and MS treatment, suggesting the potential for RSD combined with solid agricultural wastes to suppress pathogens. Furthermore, the microbial network of RSD-related treatment was more complex and interconnected, and the functions related to carbon, nitrogen, sulfur, and hydrogen cycling were significantly increased, while the functions of bacterial and fungal plant pathogens were decreased. Importantly, RSD-related treatments also significantly promoted seed germination and seedling growth. In summary, RSD combined with solid agricultural wastes is better than liquid easily degradable compounds by regulating the composition and function of microbial communities to improve soil quality and promote plant growth.IMPORTANCEReductive soil disinfestation (RSD) is an effective agricultural practice. We found that RSD combined with solid agricultural wastes is better than that of liquid easily degradable compounds, may improve soil quality and microbial community structure, inhibit the proliferation of pathogenic bacteria, and contribute to the growth of replanted crops. Thus, RSD combined with solid agricultural wastes is more effective than liquid easily degradable compounds.