Climate change on crop water requirements, irrigation, and scheduling in Jimma, Ethiopia: using CMIP6

Understanding hydro-climatic responses to climate variability is essential for sustainable agriculture in Jimma, southwestern Ethiopia. Current practices lack climate-resilient frameworks, risking inefficiencies under future warming and rainfall variability. This study integrates bias-corrected CMIP6 projections (SSP2-4.5 and SSP5-8.5), soil hydro-physical data, and maize parameters into the CROPWAT model to simulate crop water requirements (CWR), irrigation demand, and scheduling for historical (1985–2014) and future (2041–2100) periods. Results indicate a 3–10% increase in evapotranspiration, mainly due to rising temperatures and erratic rainfall. Reduced effective rainfall during key reproductive stages leads to projected gross irrigation demand increases of 15–20% by 2100. Soil moisture depletion surpasses 70% during the grain-filling phase, posing a risk to yield stability. These findings highlight the need for adaptive strategies such as precision scheduling, efficient irrigation systems, and drought-resilient practices to enhance water productivity and climate resilience in Ethiopia’s maize-growing regions.