Distribution, Environmental Risk Assessment, and Key Drivers of Microplastics in Farmland Soils Across Agricultural Zones in China

This study systematically summarized the distribution characteristics, potential sources, and ecological risks of MPs in farmland soils in China based on 35 publications. Results showed that the average abundance of MPs in Chinese farmland soils was 6715 items/kg. Regional differences in MP distribution across agricultural zones were observed. The MPs in the farmland soil were primarily in small particle sizes (0-0.5 mm) and fragments, black and transparent. Polyethylene (40.3%) and polypropylene (28.5%) were the primary polymer types. Ecological risk assessments indicated relatively high levels of MP pollution in farmland soils in China. Structural equation modeling linked mulching-film use, higher temperature, and greater precipitation to increased MP abundance, while relative humidity, altitude, and wind speed showed adverse effects. Mulching film was identified as a primary source of MPs. The findings of this study offered crucial evidence for the future monitoring and management of farmland MP pollution.