Climate Change Impact Assessment and Adaptation Strategies for Rainfed Wheat in Contrasting Climatic Regions of Iran

This is the first large-scale study to assess climate change impact on grain yield of rainfed wheat for three provinces contrasting climatic conditions (temperate, cold semi-arid, and hot arid) in Iran. Five integrative scenarios including +0.5°C temperature plus−5% precipitation, +1°C plus−10%, +1.5°C plus−15%, +2°C plus−20%, +2.5°C plus−25% were used evaluated. Nitrogen fertilizer shifting planting dates tested their suitability as adaptive strategies against changing climate. The reduced by −6.9 −44.8% temperate province Mazandaran −7.3 −54.4% arid Khuzestan but increased it +16.7% semi-arid Eastern Azarbaijan. additional application +15, +30, +45, +60 kg ha −1 nitrogen urea at sowing could not, most cases, compensate reductions under scenarios. Instead, late November, December, January enhanced +6 +70.6% all +94 +271% except scenario precipitation which led a reduction −85.5%. It concluded that production regions with climates can benefit from change, be impaired especially vulnerable like Khuzestan. Shifting date regarded an efficient yield-compensating environmentally friendly strategy regions.