Modeling climate change impacts and adaptation pathways for dry bean (Phaseolus vulgaris L.) in semi-arid Northeastern Ethiopia

Abstract

Climate change and variability pose significant abiotic threats to agricultural productivity, particularly for dry bean cultivation regions in Ethiopia. Despite the crop’s importance, modeling climate impacts and strategic adaptation was unexamined. This study evaluated the impacts of climate change and explored adaptive agronomic interventions on dry bean yield using the CROPGRO-Dry Bean model embedded in the Decision Support System for Agrotechnology Transfer (DSSAT v4.8). Historical climate data (1984–2014) from the Ethiopian Meteorological Institute (EMI) served as the baseline, while climate projections (2015–2099) were sourced from the Earth Systems Grid Federation (ESGF). Projections employed an ensemble of 11 CMIP6 climate models under SSP2–4.5 and SSP5–8.5 scenarios. The projected annual rainfall may increase by 5.1% and 9.4% in the 2040 s, 9.7% and 22.9% in the 2080 s under SSP2–4.5 and SSP5–8.5, respectively. Likewise, mean annual temperature may rise by 0.6°C and 0.99°C in the 2040 s and by 1.5°C and 3.1°C in the 2080 s, for the respective scenarios. Model calibration and evaluation also showed strong agreement between simulated and observed values. Projected seasonal rainfall, CO 2 , and evapotranspiration had positive effects, while temperature had negative effects on dry bean yields. Agronomic interventions consistently boosted grain yields under both current and projected climates. Relative to existing practices, the interaction between long-duration cultivars and high plant density may enhance yield by 36.9% under baseline, 32.6% in the 2040 s, and up to 32.0% in the 2080 s across both SSP scenarios. These findings emphasize the importance of optimizing management strategies to sustain dry bean productivity under changing climates.