Projected climate change impact on sorghum (Sorghum bicolor) yield in Fedis district Eastern Ethiopia

Abstract

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. Historical climate data was sourced from the National Meteorological Institute of Ethiopia, alongside crop yield, management data and soil samples from the Oromia Agricultural Research Institute site in Fedis. For future climate projections, data of five Global Circulation Models (GCMs) from the Coupled Models Intercomparison Project 6 (CMIP6), under the medium and high climate scenarios (SSP2-4.5 and SSP5-8.5) were downloaded from Copernicus website, and the Empirical Quantile Mapping approach was used for downscaling and bias correction. Different sowing windows and planting densities were evaluated for their effectiveness to enhance 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%. 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 2050s and 2080s 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.