• • Mean concentrations of Pb, Ni, and Cu in paddy soils exceeded Jiangxi Province background values, with Ni showing the highest ecological risk: 62.9% of Ni samples exhibited moderate risk, making it the primary pollutant requiring priority remediation.
• • PMF source apportionment quantified three sources: natural background (51.1%), industrial and mining activities (26.6%), and mixed agricultural/traffic emissions (22.3%), enabling targeted source-specific mitigation strategies.
• • XGBoost-SHAP analysis revealed that soil Fe and P contents are the dominant drivers for Cr, Ni, and Cu spatial variation, while Pb is significantly influenced by industrial and mining activities, highlighting distinct control mechanisms.
• • The integrated PMF and XGBoost-SHAP framework reduced uncertainty in source identification compared to single models, but limitations remain due to incomplete feature selection and lack of temporal dynamics, necessitating future long-term monitoring.