Assessing climate change impacts on maize yield and effects of mulching adaptation in Arba Minch, Ethiopia

Agricultural practices in Arba Minch, Ethiopia, are increasingly impacted by climate change, particularly through rainfall variability and shifting seasonal patterns. This study was conducted to evaluated climate change impacts on temperature, rainfall, and crop evapotranspiration and effects of mulching adaptation for maize canopy cover and yield improvement. Climate projections were obtained from the Coupled Model Intercomparison Project Phase 6 (CMIP6) under SSP2-4.5, SSP3-7.0 and SSP5-8.5 scenarios for the periods 2025–2054 and 2055–2084, using historical data from 2015–2024 as a baseline. The projected climate data were downscaled using the BCC-CSM2-MR regional climate model and bias-corrected with the CMhyd tool. The AquaCrop model was calibrated using local field data and used to simulate maize yield response, evapotranspiration, and canopy cover under climate scenarios. Sensitivity analysis was performed to identify key input parameters influencing model outputs. Projected temperatures increased by up to 5.8% under SSP5-8.5, with rainfall decreasing in key months like April and November. Reference evapotranspiration rose by 21.78% and crop evapotranspiration by 20.05% under SSP5-8.5 during 2055–2084. Maize canopy cover declined by up to 8.7% (non-mulched) and 7.3% (mulched) at 80 days after planting. Biomass and grain yield decreased by up to 32.4% (non-mulched) and 23.5% (mulched) under SSP scenarios. The reference harvest index showed the highest sensitivity in yield simulation, followed by water productivity and maximum canopy cover. Mean Square Error and Percentage of Error for the AquaCrop model were 0.3-ton ha−1 and 3.6% for total biomass prediction, and 0.18 kg m−3 and − 2.8% for biomass water productivity prediction, respectively. Generally, mulching demonstrated clear potential to reduce climate-induced stress on maize, improving canopy cover and yield resilience under future scenarios.