Antibiotic Resistance Genes (ARGs), a kind of contaminants of emerging concern, often occur in the reclaimed water (RW) discharged from urban sewage treatment plants. Hence, whether reclaimed water for irrigation affects the spread of ARGs in soil has become a public concern. However, the existing research conclusions lack of strict control, most of which do not take the cropping impacts into consideration, and our understanding of the underlying mechanisms is hampered due to the lack of long-term experiments.
To fill this gap, the research team of safety utilization of unconventional water resources at the Institute of Farmland Irrigation of CAAS analyzed the soil ARG profiles using metagenomic sequencing in two greenhouses with contrasting cropping systems both having received reclaimed wastewater irrigation for 16 years with the strict groundwater irrigation control. Our results showed that the cropping system but not the reclaimed water irrigation had a consistent influence, at a significant level, upon the assemblages of insertion sequences and genes conferring resistance to antibiotics, metals, and biocides. These findings provide a theoretical basis for the safe utilization of reclaimed water and highlight the significance of crop management in mitigating the dissemination of ARGs associated with RW irrigation.
Supported by the Agricultural Science and Technology Innovation Program (ASTIP) of the Chinese Academy of Agricultural Sciences, the Scientific and Technological Project of Henan Province, this work was carried out in collaboration with Beijing Water Science and Technology Institute and Rothamsted Research and published in Journal Hazardous Materials. (https://doi.org/10.1016/j.jhazmat.2021.128046).
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