Nationwide prediction of pesticide residual levels in soil: Implications on the resulting risk and prioritization framework.

Pesticides are widely accumulated in agricultural soils in China under successive applications, causing negative impacts on non-target species and environmental qualities. However, a nationwide overview of the residual levels of pesticides in soil, and the ecological risks to non-target soil species are lacking. In this study, we calculated geographically gridded concentrations of 107 pesticide active ingredients (AIs) in soils in China based on the Computational Pesticide Input (CPI) model and further assessed the ecological risks to soil biota. In the end, we proposed an integrated usage-impact model to identify prioritize control pesticides based on the usage, risk and persistence of pesticides. Pesticide concentrations were calculated in a range from 0.01 mg kg to over 185 mg kg. Glyphosate is the most prevalent pesticide that exists in most locations. The ecological risks were mostly assessed as medium risk, with extreme high- and high risk found in 1 % and 21 % of soils. Supervision and management of azoxystrbin, boscalid, butachlor and chlorpyrifos need to be prioritized. The results of this study provide guidance to local governments for the designation more accurate risk mitigation strategies across regions.