Projected Climate Change Impact on Sorghum (Sorghum bicolor) Yield in Fedis district Eastern Ethiopia

Abstract This study was conducted in Fedis district, to assess the impacts of climate change on sorghum (Sorghum bicolor L.) yield. The CERES-sorghum and APSIM-sorghum models were calibrated and validated using field experimental data of anthesis days, days to maturity and grain yield of two sorghum varieties, Melkam and Teshale. In the simulation, the initial climate data were modified by future climates under the medium (SSP2-4.5) and high (SSP5-8.5) emission scenarios. Historical climate data was sourced from the National Meteorological Institute of Ethiopia, alongside crop yield data and soil samples from the Oromia Agricultural Research Institute site in Fedis. For future projections, data from five GCMs using CMIP6 under SSP2-4.5 and SSP5-8.5 scenarios were used, and the Empirical Quantile Mapping approach for downscaling and bias correction. Different sowing windows and planting densities were evaluated for their effectiveness to increase sorghum yield under the future climate conditions of Fedis district. The results of models’ calibration and validation showed high agreement between simulated and observed grain yields, with d-stat values > 0.66 for CERES-sorghum and APSIM-sorghum, and the normalized RMSE less than 20%. However, all the models underestimated the yield. Statistical indices indicated that DSSAT-CERES and APSIM models accurately simulated sorghum yield in Fedis. The result of impact assessment showed that sorghum grain yield may increase at the range of 20.1 to 44.4% by 2030s and 2050s under both SSPs scenarios. Additionally, the result of adaptation options showed that sorghum yield may be increased through early planting date and increased plants density. In conclusion, future climate projections are expected to increase sorghum yield in Fedis and adaptations strategies including planting date and planting density can be used for better yields.