Different biodegradation potential and the impacted soil functions of epoxiconazole in two soils

Epoxiconazole is an effective pesticide to control Fusarium head blight (FHB), and the application will increase. To investigate the ecotoxicity of epoxiconazole to soil microbiome, we carried out an indoor experiment in which soils from two main regions of wheat production in China (Nanjing and Anyang) were treated with epoxiconazole (0, 0.0625, 0.625, or 6.25 mg kg^-1) and incubated for 90 days. Under epoxiconazole stress, for bacteria and fungi, the abundance was increased and the diversity and community were impacted. In Anyang soil, the half-life of epoxiconazole was short with more increased species (linear discriminant analysis effect size biomarkers) and more increased xenobiotics biodegradation pathways in epoxiconazole treatments. The increased species mostly due to high abundance in initial state and more positive connections of the species. Co-occurrences revealed that epoxiconazole tightened bacterial connection, and increased positive correlations in Anyang soil. The N transformation was influenced with increased nifH and amoA; and the contents of NH₄⁺-N and NO₃^--N were also increased. The functions of C, S, and manganese metabolisms were also impacted by epoxiconazole. This work expands our understanding about epoxiconazole degradation and help us to properly assess the risk of epoxiconazole in soil.