Influence of Self-Identity and Social Identity on Farmers’ Willingness for Cultivated Land Quality Protection

Exploring farmers’ willingness for cultivated land quality protection (WCQP) is crucial for preserving land quality. The existing sociopsychological research often examines farmers’ WCQP from a single perspective—either self-identity or social identity—overlooking the structural relationship between the two. This oversight hinders the development of synergistic policies for cultivated land quality protection. Based on a micro-survey of 439 farm households in Shaanxi Province, China, this study constructs a theoretical analysis framework for farmers’ WCQP that integrates the structural relationships of self-identity and social identity. Self-identity is further subdivided into cognitive identity, emotional identity, and behavioral identity. Using structural equation modeling (SEM), the study analyzes the impact of cognitive identity, emotional identity, behavioral identity, and social identity on farmers’ WCQP. Additionally, the moderating effects of social identity are explored. The results indicate that (1) based on the baseline regression results, farmers’ cognitive identity, emotional identity, behavioral identity, and social identity all promote WCQP among farmers; (2) the analysis of moderating effects further indicates that farmers’ social identity enhances the positive impact of cognitive identity on their WCQP. However, the moderating effect of social identity is conditional in shaping the impact of emotional identity on farmers’ WCQP. These findings remain valid after addressing endogeneity and conducting robustness tests. When farmers’ emotional identity is high, social identity strengthens its promotive effect on their WCQP, but when farmers’ emotional identity is low, social identity actually hinders this effect. Our research not only simultaneously considers both the self-identity and social identity of farmers but also delves into their structural relationship. This provides theoretical support and practical guidance for developing more targeted land quality conservation policies from a social–psychological perspective.