Impacts of climate variability on rice yield and diseases in coastal Bangladesh

Abstract Climate change has added a new dimension to the unpredictability of rice yields. Climate variability and change directly impact rice yields through fluctuations in climatic variables. Changes in temperature, rainfall, and humidity may facilitate the spread of pests and diseases, further compromising yields. Despite various studies focusing on the impact of climate variability on rice yields and diseases, region-specific mixed-methods research is scarce in coastal Bangladesh. The current study fills this gap using a mixed-methods approach over the 38 years (1981–2018). Data obtained from systematic reviews were analyzed using thematic content analysis. To assess trends in climate variables, we employed Mann-Kendall tests, and a quadratic polynomial regression was used to evaluate the influence of climatic variables on rice yields. Logit models were used to determine which climate variables were most influential on disease occurrence in rice. In the analyzed literature, 61% of studies reported a negative effect of climate variability on rice yields, while 18% reported a positive effect. The historical climate data showed significant increases in temperature (0.04 °C per year) and humidity (0.14% per year). Despite a short-term positive effect of rising temperature and humidity on rice yields, the long-term cumulative effect over the 38 years was negative. Regarding rice diseases, sheath blight increased more rapidly than blast and bacterial blight due to rising temperature and humidity. Our study concludes that sustainable rice production requires the adoption of climate-smart agriculture strategies. The government should continue and enhance policy support for developing climate-resilient crop varieties and climate-based crop disease forecasting and management services for coastal farmers. Furthermore, collaboration among government authorities, local agricultural services, researchers, and farming communities is crucial for the effective implementation of these policy strategies.