Sustainable reuse of plant waste through biofumigation: controlling soil-borne pathogens and enhancing soil health via microbial regulation.

Background: Soil-borne pathogens severely impact soil health and crop growth. Biofumigation is an eco-friendly method and supports global efforts to reduce chemical fertilizers and pesticides. However, the application in China is limited mainly due to high cost. There is a lack of systematic research on how plant waste biofumigation can improve soil health. We were the first to systematically examine the effects of biofumigation with cabbage and cauliflower wastes on soil and plant factors, and their contributions to crop growth.

Results: Results indicated that biofumigation achieved an inhibition rate of soil-borne pathogens between 66.98% and 92.70% at the end of the process, which persisted at 52.89-83.95% during harvest. Additionally, it enhanced soil physicochemical properties, enzyme activity, and the abundance of beneficial microorganisms by 0.41-119.12%. Crop yield also increased by 21.70-77.83%. Comparing the standard cabbage treatment with a higher dosage revealed that the latter did not significantly enhance pathogen inhibition rates but improved yield, suggesting the involvement of alternative mechanisms. A structural equation model revealed that Firmicutes and Bacteroidota increased crop yield by influencing ammonium nitrogen, organic matter, and catalase activity, with ammonium nitrogen being the most significant factor (0.74).

Conclusion: These findings suggest that biofumigation with Brassica waste provides effective control of soil-borne pathogens at a reduced cost. Additionally, it improves soil fertility and can partially replace chemical fumigants and fertilizers. By minimizing chemical inputs, biofumigation contributes to improved soil health and sustainability. © 2025 Society of Chemical Industry.