Water stress dominates the projected maize yield changes in Ethiopia

In Ethiopia, a highly food-insecure nation, traditional agriculture faces significant climate change challenges. Long-term food security planning and famine prevention efforts require a comprehensive assessment of how crop yield might change in the future across the whole Ethiopia at a spatial scale usable and useful for local decision making. In this study we aimed to assess future climate-induced maize yield changes in Ethiopia and identify the primary stress factor that limit regional agricultural productivity using a high-resolution process-based crop model (DSSAT) forced by multiple regional climate projections from CORDEX-Africa under the Representative Concentration Pathway 8.5. The climate projections were statistically downscaled and bias-corrected for local relevance before used as input to the crop model. It was found that without technology advancement and management practice changes, climate change would cause the Ethiopian maize yield to decrease from-1400 kg/ha in present day climate to-900 kg/ha by late century, primarily due to increased water stress during critical growth stages caused by changing precipitation patterns and rising temperatures. While the most productive regions may suffer significant yield losses, some less productive areas might become more suitable for maize cultivation, indicating a possible spatial shift in agricultural productivity. These findings should be considered in developing climate adaptation strategies at the individual farming communities, national, and international levels. Climate change will offset at least some of the yield boosting power of agricultural technologies in Ethiopia and challenge the future food security of a growing population.