Effect of Climate Change on Wheat Yield and Water Productivity in Iran and the World

Climate change (CC) has affected all parts of the world, including Iran. The effect of CC on agriculture is mainly related to crop growth, agricultural production and water resources. This paper analyzes the effects of CC on wheat, a strategic crop in Iran and the world, as changes in yield, water requirements and water productivity from scientific papers and reports. CC has had adverse effects on wheat yield, especially rain fed wheat, in Iran and other parts of the world. By changing the environmental parameters, it is estimated that CC will lead to a 10-14% decrease in wheat yield. Some studies have shown that the percentage of changes in wheat yield is even higher than these values. The most important factor is the increase in temperature and heat stress on this plant. CC can reduce the crop growth period and produce associated adverse physiological effects such as reducing the planting to flowering period, shortening the seed filling period and reducing the flowering to maturity and seed production period. The proposed adaptation measures include development of crop cultivars that are tolerant to heat stress and with low water requirements, cultivars with longer growing periods, changes to planting dates, better on-farm water management, crop residue management, and increasing the level of organic matter in the soil. It is suggested that the strategies for coping with CC in wheat production should focus more on reducing the effects of rising temperatures and heat stress on the wheat plant, especially in its critical growth stages. Therefore, it is necessary to mainstream the effects of CC on agriculture, especially on strategic crops, in terms of ensuring food security and prioritizing it in national and sub-national research studies, especially in Iran.