Elucidating the potential of soil transplantation in mediating disease suppression against phytopathogens in wheat

Sustainable agricultural practices employ diverse bio-amendments in fields, which enhance microbial abundance and activity in soil, rendering the disease suppressive trait in soil. The present study was conducted with an aim to decipher what minimum fraction of suppressive soil from a specific organic field, upon mixing with a conventional field soil, could retain disease suppressive trait in transformed soil. Using wheat as model crop, disease suppression assays were conducted under natural conditions in clay pots against the broad host range pathogens, Rhizoctonia solani, Fusarium oxysporum, and Sclerotium rolfsii. Mixing 1%, 5%, 10%, 15% and 20% of organic soil fraction with conventional field soil, resulted in variable impacts of disease suppression against phytopathogens in wheat at the flowering and harvest stages. For crop cultivation, transplanted soil comprising 1% organic soil in combination with conventional soil, exhibited promising impacts on plants and soil. For majority of the treatments, this trend was comparable with 100% organic soil treatment, both under biotic stress and non-stress conditions, as witnessed by enhanced plant growth attributes, reduced disease severity, soil physicochemical factors and enzymatic marker levels and reaffirmed by dose-response relationship analysis. The study highlighted that mixing conventional field soil with defined fraction of suppressive soil from organic field can significantly improve plant fitness and mediate pathogen biocontrol. This strategy can promote effective disease management and agricultural sustainability across diverse agroecosystems.