How does rural industrial integration affect farmers’ income?—An empirical study based on Jiangxi Province

Introduction Amid global economic shifts and rural decline, promoting rural industrial integration has become a core strategy for China’s Rural Revitalization and sustainable farmers’ income growth. However, existing studies mostly focus on macro-policy interpretation or case descriptions, lacking mechanism testing and heterogeneity analysis based on large-sample county-level data. Jiangxi Province, a typical agricultural province with distinctive terrain and urgent rural industrial revitalization needs, provides an ideal empirical context. This study aims to systematically explore the impact, transmission mechanisms, and heterogeneous characteristics of rural industrial integration on farmers’ income. Methods Using panel data from 95 counties in Jiangxi Province during 2014–2023, we constructed a Rural Industrial Integration Index (RIII) covering four dimensions: chain extension, multi-functionality expansion, multiformat integration, and technology penetration. A combination of two-way fixed effects models, mediating effect models, and full quantile regression methods was employed to conduct empirical analysis. Results The RIII exerts a significantly positive effect on farmers’ income: every 1% increase in the RIII leads to a 3.1–3.3% growth in rural residents’ Per Capita Disposable Income (PCDI). Non-agricultural employment serves as a key transmission mechanism, with its mediating effect contributing 23.74% of the total effect. The income-increasing effect exhibits notable heterogeneity, being more pronounced in middle-low income counties, hilly terrain areas, and central Jiangxi regions. Discussion This study enriches agricultural economics theories by verifying the causal relationship between rural industrial integration and farmers’ income. The findings provide empirical evidence for formulating regionally differentiated rural industrial integration policies, offering critical decision-making insights for boosting farmers’ income growth and advancing rural revitalization strategies in Jiangxi and similar agricultural regions.