Effects of ammonium sulfate on the degradation and metabolism of dinotefuran in soil: Evidence from soil physicochemical properties and bacterial community structure.

Ammonium sulfate and dinotefuran are widely used in agricultural practices; however, limited knowledge exists regarding the potential risks associated with their co-exposure. In this study, the impact of ammonium sulfate on the degradation of dinotefuran in four soils was investigated, and the formation of the main metabolites UF, DN, MNG, and NG was also determined. The underlying mechanisms were explored by the impact of ammonium sulfate on soil physicochemical properties as well as soil microorganisms. The half-life of dinotefuran sole exposure in soils were determined between 27.47 and 60.05 days. Co-exposure of ammonium sulfate significantly impeded the degradation of dinotefuran, resulting in 1.70-5.05 times longer half-life, reduced the content of the metabolites and changed their composition. Ammonium sulfate induced significant alterations in the structure and dominance of bacterial communities in the soils. The reduced relative abundance of Bacteroidota, Proteobacteria and Chloroflexi phyla related to dinotefuran degradation. Ammonium sulfate also led to a decrease in soil pH and organic matter content, which were negatively correlated with the degradation. PLS-SEM analysis revealed soil microbial diversity had a significant impact on the degradation of dinotefuran. The findings serve as a cautionary note regarding the risks of co-exposure to fertilizers and pesticides.