Simulated adaptation strategies for spring wheat to climate change in a northern high latitude environment by DAYCENT model

In order to identify strategies to support global food security while protecting the environment under future climate in northern high latitude environments such as the Canadian Prairies, the DAYCENT model was calibrated, validated, and subsequently used to project effects of climate change (increased carbon dioxide concentration, precipitation, and temperature), nitrogen (N) application rate, and yield potential (radiation use efficiency of biomass, RUEB) of spring wheat (Triticum aestivum L.) on yield production and environmental outputs. Results indicated that projected grain yield and environmental impacts, i.e. soil organic carbon (SOC), N leached below root zone and nitrous oxide (N2O) emission, are affected by different climate change scenarios, N fertilizer rate and RUEB. From these results, we can assess impacts of fertilizer rates on projected grain yield and environmental impacts (SOC, N leaching and N2O emission) in the near future (2017-2046) and distant future (2047-2076). In the near future, if wheat RUEB is improved from current 38-43 mg C kJ−1, the projected yield over seven climate change scenarios will increase 35% with a fertilizer rate of 100 kg N ha−1 compared to the current rate (50 kg N ha−1). Corresponding increases of N leaching, N2O emission and final SOC in 2046 are 29, 35 and 12%, respectively. Additional increases of yield and SOC will be small if more N is added, while N leaching and N2O emission will be further increased. Assuming the cultivar grown in the distant future is improved to 53 mg C kJ−1 RUEB and the fertilizer rate is raised to 125 kg N ha−1, projected yield, N leaching, N2O emission and final SOC in 2076 will be increased by 69, 26, 56 and 80%, respectively. If the N input is increased to 150 kg N ha−1, corresponding increases will be 83, 30, 103 and 151%. It seems that appropriate N input could be 100-125 kg N ha−1 for the near future and distant future, respectively in order to balance production and environmental impacts. Results of our study indicated that after modification and calibration, DAYCENT model can be used to identify adaptation strategies for food security and environmental protection in high latitude environments under future climate change.