Modeling climate change impacts on chickpea growth and yield under RCP climate scenarios and evaluating adaptation strategies in central Ethiopia

Abstract

This study aims to investigate the impact of climate change on chickpea yield and explore best-fit adaptation strategies for yield optimization. Crop data from 2010 to 2017 were used for model calibration, and from 2020 to 2022 were used for model evaluation. The CROPGRO module under the Decision Support System for Agrotechnology Transfer (DSSAT) crop model was applied. Baseline (1971–2009) and future (2010–2039) weather data under the RCP4.5 emission scenario were downscaled from the Coordinated Regional Downscaling Experiment (CORDEX) Africa domain. Model evaluation results revealed the goodness of fit (R 2 ) is 83% for flowering day, 84% for grain yield, and 86% for physiological maturity. At the end of 2040, the projected rainfall is expected to vary substantially, ranging from a 20% decrease to a 50% increase under the RCP4.5 emission scenario. In contrast, both maximum and minimum temperatures are projected to increase, with positive changes ranging from 0 to 20%. Days to flowering (DOF) are projected to decrease by an average of 5.5%, while days to maturity (DOM) decrease by an average of 2.8%. This indicates that increasing temperature accelerates chickpea development and reduces the crop growing season. At the Debre Zeit site, projected yield changes range from a 42.0% reduction to a 43.3% increase. Similarly, at the Cheffe Donsa site, yields are projected to vary between a 27.1% decrease and a 58.3% increase, while at the Minjar Shenkora site, yields are projected to vary between a 35.1% decrease and a 62.5% increase. This indicates that chickpea yield is expected to show considerable spatiotemporal variability across the years and sites. Planting on August 15 is optimum for the chickpea crop at the Debre Ziet site, while planting on August 20 and August 1 are suitable for the Cheffe Donsa and Minjar Shenkora sites, respectively. Planting time is an ideal adaptation strategy that can optimize chickpea yield, while applying fertilizers and tillage have little effect on chickpea yield.