Sensitivities of Wheat and Maize Productivity in Kazakhstan to Future Climate Change Scenarios.

Crop productivity is sensitive to climate change, especially in arid Central Asia, where few studies have been conducted on how crop productivity responds to global climate change. Based on the history of yield trends of major crops in Kazakhstan, this study proposed a quantitative method to estimate the sensitivity of relative crop yields to agro-technique development and temperature rise in Kazakhstan. Taking wheat and maize as typical crops, this research attempted to assess the potential impact of future global climate change scenarios on crop yields in 14 agricultural areas of Kazakhstan, based on the interaction between agro-technique development and climate change. The effects of future agro-technique development were assumed to be consistent with historical trends, which were expressed in a second-order polynomial form and adjusted by the disparity between actual yields and predicted yields. The parameters representing technology development were determined by the special report of the Intergovernmental Panel on Climate Change (IPCC) on emission scenarios and the future temperature was predicted by the global climate change model, IPSL-CM5A-LR Model (ICLM). In this study, 2060 and 2100 were selected as assessment years. The results showed that crop yields will continue to increase until 2060 under future climate change scenarios, but the estimates of yield changes after 2060 are subject to great uncertainty in the longer term. By 2100, the impact of temperature rise on crop productivity will be greater in the southern and eastern areas than that in the central and western areas. Crop productivity will be improved with the combined impact of temperature and technology under Representative Concentration Pathway 2.6 (RCP2.6), Representative Concentration Pathway 4.5 (RCP4.5) and Representative Concentration Pathway 6.0 (RCP6.0) by 2060. However, compared with 2060, the relative yields of the two crops will be improved under RCP2.6, RCP4.5 and RCP6.0 scenarios by 2100. By contrast, the results under Representative Concentration Pathway 8.5 (RCP8.5) are not uniform: the yield of wheat will decrease by 7.4%, while that of maize will increase by 23.86% compared with 2060. The contribution rate of agricultural technology to improving maize yield is higher than that to wheat yield and maize is less sensitive to temperature than wheat in terms of yield. The wheat yield increases the most in the RCP4.5 scenario and the maize yield increases most in the RCP6.0 scenario. Considering that the wheat yield counts for more than 70% of crop production in Kazakhstan, it is suggested that emissions are controlled to reach the RCP4.5 standard and maximize the agricultural yields. [ABSTRACT FROM AUTHOR]