Background
Rice (Oryza sativa) is the most important staple food for almost half of the global population. Improvement of rice yield is of global concern and is influenced by a wide variety of regional factors including climate and agricultural management. This research addresses the need to understand the relative influence of these factors and develop geographically explicit determinants of rice yield across Bangladesh. The specific objectives of this study were (a) to assess spatial and temporal variation in rice yield, cropping intensity and means of irrigation, and (b) to evaluate the relative importance of spatio-temporal change in climate, cropping intensity and means of irrigation on rice yield. A database on rice yield, management practices (cropping intensity and means of irrigation) and climate was collected from the Bangladesh Bureau of Statistics and Bangladesh Meteorological Department, respectively, for the years of 1981–2010. Linear mixed models were used to assess the influence of different determinants on rice yield.

Results
The results indicate that irrigation, particularly groundwater irrigation, had a stronger influence on rice yield than climatic conditions and cropping intensity in Bangladesh during the study period. Temperature and rainfall showed negative impacts on yield. Rice yield also declined when cropping intensity increased.

Conclusions
Both climate and groundwater extraction need to be considered in future policy development. However, the current extraction rate of groundwater may not be sustainable in the future to increase rice yield. The study concludes that spatio-temporal differences in observed yield allow interpretation of potential determinants that are important for food policy development in Bangladesh.