The investigation of adaptation methods to drought and climate change for wheat plant using AquaCrop vegetation model

Abstract

Climate change-induced drought severely threatens agricultural productivity, posing an irreparable risk to food security, particularly for staple crops like wheat cultivated in severely arid regions. This study focuses on Birjand, Iran, a critically vulnerable agricultural zone, to quantitatively assess the impact of future climate change on wheat production and to test actionable adaptation strategies. The research utilized the field-calibrated AquaCrop model to project grain yield and bio- mass for three locally important wheat cultivars (Arg, Roshan, and Sirvan) under two key IPCC scenarios (RCP 4.5 and RCP 8.5) across future periods. The primary novel contribution of this work lies in its field-validated calibration of the AquaCrop model for this specific arid environment, providing a robust, localized forecast. Key findings reveal that climate change significantly suppresses yield potential, with the high-emission RCP 8.5 scenario causing yield reductions exceed- ing 50% across all treatments. Among the management options investigated, the ‘Sirvan’ cultivar demonstrated superior resilience, suffering the lowest overall reduction. Furthermore, the analysis confirmed that delaying the planting date is highly detrimental, as the latest sowing date consistently led to the greatest yield losses, particularly under the severe RCP 8.5 pathway. The overriding implication for policymakers and farmers is that maintaining early planting schedules is essential, and prioritizing the cultivation of resilient varieties like ‘Sirvan’ is the most effective strategy to buffer against projected catastrophic yield decline in this semi-arid region.