Mesosulfuron-methyl influenced biodegradability potential and N transformation of soil.

Abstract The wide application of mesosulfuron-methyl (MS) in soil may affect soil microbial community, yet the information is limited. In this work, two distinct soil types from Anyang (AY) and Nanjing (NJ) were spiked with MS (0, 0.006, 0.06, or 0.6 mg kg–1) and incubated for 90 days. MS decreased bacterial and fungal (except the last sampling) abundance and altered their diversity and community. Five biomarkers of bacterial species may help MS degradation and more increased xenobiotics biodegradation pathways were also observed in 0.6 mg kg–1 treatment in AY soil. A co-occurrence network revealed the biomarkers grouped in one module in all AY soils, suggesting these biomarkers act in concert to degrade MS. MS impacted soil N transformation with increasing N2-fixing bacteria in both soils and ammonia-oxidizing bacteria (AOB) in NJ and decreasing ammonia-oxidizing archaea (AOA) in AY. The contents of NO3–-N and NH4+-N were increased by MS. Structural equation models revealed that the abundance of bacteria and fungi was responsible for the NO3–-N and NH4+-N contents. In conclusion, this work aids safety assessments and degradation-related research of MS in soil.