Drivers of crop diversification in a semi-arid region: Evidence from Vellore district, South India

Agricultural systems in the semi-arid tropics of India are increasingly susceptible to climate variability, posing significant challenges to productivity and rural livelihoods. This study examines the determinants of crop diversification in the Vellore district of Tamil Nadu, with a particular emphasis on climatic, socioeconomic, and institutional factors. The analysis integrates cross-sectional farm-level data with long-term climatic data spanning the period from 2001 to 2019. Crop diversification was quantified using the Herfindahl Index and Crop Diversification Index, and regression models were employed to identify key drivers of diversification and sustainability outcomes. The results indicate that climatic variables, such as rainfall and temperature, had a limited direct influence on diversification decisions. Conversely, institutional factors -particularly extension contact -emerged as more consistent drivers. Sustainability outcomes were significantly influenced by technology adoption, farm size, income stability, and climate perception. The findings suggest that diversification alone does not ensure resilience in semi-arid agricultural systems; rather, integrated institutional support and access to climate-smart technologies play a more critical role. This study contributes to the growing body of literature by demonstrating that crop diversification in semi-arid regions is shaped more by socioeconomic and institutional dynamics than by short-term climatic variability, offering important policy insights for similar agro-ecological contexts.