Rural labor transfer, non-farm income and agricultural non-point source pollution: evidence from China

The prevention and control of agricultural non-point source pollution (ANPP) is vital for promoting green agricultural development and has become a key public concern. Using statistical data from 30 provinces in China during 2005–2022, this study empirically investigates the influence mechanism and threshold effects of rural labor transfer on ANPP, employing a comprehensive framework including benchmark regression, mediating-moderating effect models, and threshold regression, supplemented by instrumental variable (IV) techniques to address endogeneity. Key findings include: (i) Rural labor transfer significantly exacerbates ANPP, with heterogeneous effects across rural labor transfer types and regional contexts. (ii) A single threshold effect exists, demonstrating a non-linear pattern where the marginal impact of rural labor transfer on ANPP diminishes as its scale increases. (iii) Non-farm income serves as a critical mediating pathway through which rural labor transfer intensifies ANPP. (iv) Agricultural socialized services moderate this effect by mitigating the mediating role of non-farm income, thereby alleviating environmental degradation. These findings provide policy insights for China to optimize ANPP prevention strategies, highlighting the need to coordinate labor migration management, income diversification, and agricultural socialized services development for sustainable agricultural growth.