Bacterial communities driving cabbage yield increases and pathogenic risks reduces following wastewater irrigation: Effects of nitrification inhibitors on different soil-vegetable systems

Wastewater irrigation has the potential to enhance crop productivity but could have negative impacts on soil-vegetable systems health. This study was conducted to explore the effects of wastewater and nitrification inhibitors dicyandiamide (DCD), and 3,4-dimethylpyrazole phosphate (DMPP) on the soil potential pathogenicity and vegetable yield in different soil-vegetable systems. The extra DMPP significantly increased cabbage yield by improving vegetable quality, increasing the endophytic bacterial community diversity, and enhancing nirB gene abundance, compared with wastewater irrigation alone. Compared with control treatment, wastewater irrigation alone increased soil potential pathogenicity by 17.39 % and 2.58 % in neutral and acidic soils, respectively. Relative to the wastewater irrigation alone, the extra DMPP could reduce soil potential pathogenicity in neutral and acidic soils by 2.87 % and 5.50 % via increasing the endophytic bacterial community stability and increasing the proportions of soil Myxococcota, Gemmatimonadota, Actinobacteriota and Proteobacteria, respectively.