Impacts of climate change on paddy yields in different climatic zones of Sri Lanka: a panel data approach

While climate change affects agricultural production globally, scarce literature has quantified the impacts of climatic factors on paddy yields with attention to specific water regimes, climatic zones, growth periods, and crop seasons. This study aimed to identify the effects of various climatic variables at different plant growth phases (growing and harvesting), crop seasons (Maha and Yala) [In Sri Lanka, there are two main crop seasons. Maha is the major cultivation season covering the months of October to March, and Yala is the minor cultivation season covering the months of April to September], and water regimes (major irrigation, minor irrigation, and rainfed) in three climatic zones (dry zone, intermediate zone, and wet zone) of Sri Lanka. A district-wise annual panel dataset was constructed for a 39-year period (1981 to 2019) covering 18 districts and analyzed by panel regression methods. The results showed that temperature had significant non-linear effects on yields in the dry and intermediate zones. Variation in temperature decreased yields more in the dry zone than in other zones. Rainfall significantly reduced yields in the dry and wet zones, whereas it increased yields in the intermediate zone. Rainfall fluctuations decreased yields in the wet zone more than in other zones. These findings suggest a need for dissemination of climate-smart agriculture practices by considering the characteristics of each water regime, particularly in the dry zone. For rainfed paddies, a crop insurance scheme should be introduced to reduce crop losses due to harsh climatic events. Complementary policies, such as improvement of irrigation systems and provision of timely weather forecasts, can support smallholder paddy farming.