The Soil Health Care Innovation Team of the Institute of Agricultural Resources and Regional Planning (IARRP) of the Chinese Academy of Agricultural Sciences (CAAS) and the CAAS-CIAT Sustainable Agriculture Joint Laboratory conducted research on the effects of long-term exposure to the herbicide nicosulfuron on the spatial distribution of environmental microbial communities, revealing the effects of herbicide exposure on microbial diversity and the main factors that cause differences in microbial community structure. This study has important implications for more accurate herbicide residue risk assessments and feasible pollution remediation strategies.

The results of their research were published in the journal Environmental Pollution.

According to associate professor Ruan Zhiyong, nicosulfuron is the leading global sulfonylurea herbicide and has been widely used to control weeds in corn fields in China for more than 30 years. However, the effects of long-term use of nicosulfuron on the health and safety of soil ecosystems are unclear.

Environmental samples were collected from a factory that produced nicosulfuron for more than 20 years, and the composition and characteristics of microbial community structures and the  interaction networks in different samples such as soil, water and sludge exposed to  nicosulfuron  for a long-term were analysed using high-throughput seguencing technology.

The results showed that the main contributor to the differences in the microbial community structure was the sample type, followed by oxygen content, pH and nicosulfuron residue concentration in the factory. Long-term nicosulfuron exposure increased bacterial and archaeal alpha diversity. The dominant groups in the environmental samples from the factory were Bacteroidetes, Actinobacteria and Proteobacteria.

Based on the interaction between microorganisms, the bacterial co-occurrence network of the environmental samples in the factory was constructed, the key node microorganisms in the network were isolated, and the nicosulfuron-degrading Synthetic community (SynCom)was constructed. The results of network analysis and degradation evaluation showed that Rhodococcus sp. was not only a key bacterial genus in the long-term exposure environment of nicosulfuron, but also improved the degradation efficiency of the SynCom.

Ma Qingyun, a 2018 graduate student of IARRP, and Tan Hao, a 2019 graduate student, are the co-first authors of the paper. The research was funded by the National Natural Science Foundation of China, and the Fundamental Research Funds for Central Non-profit Scientific Institution, and the Science and Technology Innovation Project of CAAS.

Paper link:

https://doi.org/10.1016/j.envpol.2022.119477

https://authors.elsevier.com/a/1f7IizLNSc7z-  (Free download for a limited time)