Uncertainty of climate change impact on crop characteristics: a case study of Moghan plain in Iran

Crop yield is one of the most critical factors in the food security chain. Climate plays a crucial role in crop water productivity in rainfed and irrigated crop productions. Climate changes would significantly impact crop characteristics, especially in Iran, where water is the major constraint of crop production. This study assessed the impact of climate change on crop water productivity with related uncertainty. The global climate model simulations of rainfall and temperature were statistically downscaled using LARS-WG6 for climate projection. The projected climate was used in the FAO AquaCrop model to simulate the variability of crop characteristics (crop cycle length, crop yield, and water productivity) for the assessment of climate change effect on major crops for three future horizons (2021–2040, 2041–2060, 2061–2080). Results revealed an increase in wheat yield by 14 − 54% and a decrease of growth duration by 1 − 12%, leading to an increase in water productivity by 9 − 96% in the future compared to the base period (1985–2016). In contrast, reduction in corn and soybean yield by 1 − 5% and 2 − 6% and growth period by 1 − 5% and 3 − 12%, and thus, an increase in water productivity by 1 − 9% and 2 − 24%, respectively, were projected. The growth duration of all the major crops was projected to decrease due to a rise in temperature and an increase in crop water productivity in the study area. The results indicate a more favorable condition for crop agriculture in the study area under the projected climate.