Stillage-based reductive soil disinfestation with organic materials reshapes the microbiome of continuous tomato soil...

Reductive soil disinfestation (RSD) can suppress soil-borne diseases in continuous cropping systems, yet the effectiveness of stillage and distillers' grains and the soil mechanisms associated with their use in tomato remain unclear. Here, we tested stillage-based RSD with or without solid amendments (distillers' grains, corn straw or sheep manure) and assessed plant performance, soil properties, enzymes activities and microbial community responses.

All RSD treatments increased tomato biomass and reduced the disease index. RSD increased soil pH, ammonium nitrogen (NH₄ ⁺-N), available phosphorus (AP) and labile organic carbon, while decreasing nitrate nitrogen. Bacterial communities were strongly reshaped, with enrichment of Firmicutes, Bacteroidota, and anaerobic fermenters (e.g. Proteiniphilum, Azospira) and depletion of Nitrospira and Fusarium. NH₄ ⁺-N, AP and pH were associated with microbial community composition and plant performance. Canonical correspondence analysis (CCA) and Mantel tests indicated that these variables were among the soil properties most closely linked to microbial community patterns and tomato growth under RSD.

Our findings demonstrate that stillage-based RSD, when co-applied with distillers' grains, sheep manure, or corn straw, effectively mitigates tomato continuous-cropping obstacle and promotes the valorization of liquor by-products by reconstructing a beneficial soil microbe-plant-nitrogen network. © 2026 Society of Chemical Industry.