Investigating the Impact of Compound Extremes on Crop Yield Response of Cotton Using DSSAT-CROPGRO-Cotton Crop Simulation Model

Abstract

Agricultural productivity is highly vulnerable to weather and climate extremes, including droughts and heatwaves, which can significantly impact crop yields. Despite previous studies addressing the effects of individual and compound extremes on crop productivity, a comprehensive understanding of the critical duration thresholds beyond which a crop yield declines substantially remains limited. This study aims to investigate the duration thresholds of compound and individual extremes for cotton under various scenarios. We utilize the decision support system for agrotechnology transfer-cropping system growth model (DSSAT-CROPGRO)-Cotton crop simulation model, combined with bias-corrected projections from eight climate models, to simulate future cotton yields for rainfed and fully irrigated conditions with varying CO2 concentrations. Our findings indicate an overall decline in cotton yields across all scenarios toward the end of the century, with the highest emissions scenario (SSP585) showing the most significant reduction. The occurrence of coincidental heatwaves and droughts in SSP585 leads to yield declines of approximately 33%, 23%, and 15% in S1, S2, and S3 scenarios, respectively. While rainfed scenarios with increased CO2 show some mitigation of extreme events’ impact, fully irrigated scenarios exhibit only marginal improvements. These results underscore the urgency of developing sustainable practices to mitigate the adverse effects of extreme events on cotton yields amid a changing climate.