| Abstrakt: |
Climate change is the main consequence of the increased rate of greenhouse gases (GHG) emission and accumulation (e.g., CO2) in the atmosphere. As more GHG is accumulated in the atmosphere, mean temperature of the Earth rises, changing the air pressure patterns. With the change in these patterns, rainfall pattern and frequency are changed throughout the world. Therefore, the investigation into the impact of this phenomenon on crop production is among the main actions required for food security. The present study aimed to explore the effect of future climate change on yield and water productivity of wheat production under rain-fed conditions in Iran for which the new protocol presented by the GYGA (Global Yield Gap and Water Productivity Atlas) was run for the whole country. Potential yield (Yp) was estimated by the SSM-iCrop2-wheat model for a 15-year period (2000–2014). The results of weather data produced by the HadGEM general circulation model with the output of Agmep model with the RCP of 4.5 and 8.5 showed the response of wheat growth and yield in two periods of near future (2055–2085) and far future (2085–2099). Among all studied scenarios vis-à-vis status quo, rain-fed wheat yield will increase in all DCZs except for DCZ 7003 and DCZ 6002 (i.e., the Masjed Soleyman and Pol-e Dokhtar stations, respectively). DCZ 3103 (the Bostanabad station in East Azerbaijan province with cold climate) showed a positive impact of 181% variation (from 1776 kg ha−1 under status quo to 5003 kg ha−1 under 2092–8.5 scenario), and DCZ 7003 (the Gonbad station in Golestan province) showed a negative impact of −13.9% variation (from 2765 kg ha−1 under status quo to 2378 kg ha−1 under 2092–8.5 scenario). The assessment of these scenarios revealed that climate change affects yield significantly (p < 0.01). Means comparison showed statistically significant differences between status quo and future periods in terms of the yield of rain-fed wheat. In all DCZs across Iran, the highest yield (4821 kg ha−1), water productivity (2.17 kg m−3), and transpiration efficiency (9.28 g mm−1) were related to the scenario of 2085–2099 with the CO2 level of 825 ppm (for the year 2092) as the far future with RCP8.5. [ABSTRACT FROM AUTHOR] |
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