Simulating the impact of climate change on production of chickpea in Zanjan province

Climate change due to increase atmospheric CO2 concentration and other greenhouse gases could have considerable effects on crop production in the future. The aim of this study was climate change impacts on chickpea yield in rainfed condition and generating yield map in Zanjan province، Iran. Investigated scenarios were historical climate (control) and future climate scenario that included both direct effect of doubling CO2 (350 to 700ppm) and its indirect effects (10% reduced rainfall، 4ºC increase in temperature). Simulations were done using a simulation model of chickpea and Geographical Information System (GIS) approach was used to produce yield maps. Grain yield and its variability were evaluated in comparison to current trend. The future climate condition will increase crop yield by 33. 4% (717 to 957 kg ha-1 depending on location)، but yield variability will increase by 21. 2%. Increasing in grain yield was a result of positive effect of doubling CO2 on photosynthesis and resultant decrease in transpiration. The results also showed that increasing temperature was the main reason of higher yield variability. Zanjan station with an increase of 46. 5% in grain yield showed the greatest yield increase under the future climate but yield variability at this location was also increased by 37. 7%. The highest grain yield was simulated for Khodabandeh station under both current (1307 kg ha-1) and the future (1385 kg ha-1) climates.