Environ Monit Assess. 2026 Apr 9;198(5):422. doi: 10.1007/s10661-026-15294-1.
ABSTRACT
Heavy metal pollution in regional and global agricultural soils is an increasing concern, especially under the current context of frequent extreme climate events. In this study, we investigated the distribution characteristics of heavy metals in typical Chinese farmland soils under varying fertilization levels, precipitation intensities, and crop types. We employed a structural equation model (SEM) and random forest model (RFM) to elucidate the effects of precipitation, fertilizer application, soil properties, and other factors on the heavy metal content of farmland soils. Our findings demonstrated that level III fertilization posed the highest ecological risk of heavy metal contamination (ecological risk index (RI) = 219). Medium contamination risk was observed in areas with precipitation > 800 mm and precipitation of 400-800 mm (1 < pollution load index (PLI) ≤ 3). The RI (610) was 5.71 times higher in rice-wheat rotation areas than in areas with other crops. Geospatial, soil physicochemical properties, precipitation, and pesticides significantly impact heavy metal concentrations (p < 0.05). Furthermore, SEM and RFM have elucidated the distinct pathways through which diverse influencing factors affect soil heavy metal content, along with quantifying the magnitude of each contribution. Our results suggest that the escalation of precipitation (extreme and average precipitation) and the heightened intensity of human agricultural activities are exacerbating the deterioration of heavy metal contamination in agricultural soils. This research provides essential foundational data and significant references for the mitigation of heavy metal pollution in farmland soils.
PMID:41951982 | DOI:10.1007/s10661-026-15294-1
