Peer Effects and Ecological Rationality: A Study on the Intention–Behaviour Discrepancy in Rice Farmers’ Organic Fertiliser Adoption for Agricultural Sustainability

Against the backdrop of global agricultural sustainability transition, this study examines the mechanism through which peer effects influence the intention–behaviour paradox in farmers’ adoption of organic fertilisers as a substitute for chemical fertilisers, from the perspective of ecological rationality. Using survey data from 505 rice farmers in Hunan Province, this research integrates peer effects and ecological rationality into a unified analytical framework and employs a Probit model to test the mediating role of ecological rationality in the relationship between peer effects and the intention–behaviour gap in chemical fertiliser reduction for sustainable farmland management. The results show that support from family members and people in one’s immediate social environment can effectively alleviate the intention–behaviour paradox among farmers in the process of substituting chemical fertilisers with organic fertilisers, whereas support from friends is positively correlated with this degree of discrepancy. Ecological rationality serves as a mediating variable that strengthens the positive effect of peer influence on the consistency between farmers’ behavioural intentions and actual practices in sustainable agricultural production. These findings provide a new theoretical perspective for understanding farmers’ pro-environmental behaviour, and offer actionable policy implications for advancing agricultural sustainability by enhancing family and community support and improving farmers’ ecological rationality.