Off-farm employment and nonpoint source pollution from chemical fertilizers in China: mediating role of farmland transfer

Agricultural nonpoint source pollution (NSP) is a growing environmental threat in developing countries. Examining the factors influencing NSP can benefit pollution control. This study investigated the impact of off-farm employment on NSP originating from chemical fertilizers and the mediating role of farmland transfers in this relationship in China. Panel regression analysis is adopted in this study. The results show that the farmland transfer scale directly and negatively impacts the discharge intensity of NSP from chemical fertilizers. However, above a certain threshold, the expanded scale of transfers controls off-farm employment, leading to a higher NSP discharge intensity. In addition, off-farm employment also depends on several features of agricultural production and farmer households, thereby influencing the NSP discharge intensity. Whether the influencing relationships are positive or negative is determined by the thresholds in the features of agricultural production and of the household. This study suggests that an emphasis be placed on rural labor transfer, agricultural output growth, and green land utilization, considering regional differences in policy implementation areas.