Analysis On Impact Of And Adaptation Measures To Climate Change On Wheat Production

With global warming, the climate in China has changed significantly, and it had a great impact on agriculture. Wheat is the second important food crop in China, and it occupies an important position in the national economy. Assessment of the impact and adaptation of climate change on wheat production in China is of great significance.In this study, wheat experiment data at 36 wheat stations from 1981 to 2000 was used to verify the application of CERES-Wheat model in China and analyze the sensitivity of the crop model; outputs of PRECIS driven by ERA were employed to crop model to validate the linkage approach of PRECIS outputs with crop model; simulate and evaluate the change of wheat growth period and yield under A2 and B2 scenarios in 2080s (2071~2100) relative to that in baseline (1961~1990); on the basis of the impact evaluation, we try to study some adaptive measures such as adjusting sowing time, cultivating and introducing new wheat varieties.The main results of this research are as follows:(1) From the simulation by CERES-Wheat model, we can see that the simulated growth period and yield has a better consistency with the observed value, and the error between outputs of crop model and observations is within a reasonable range. It shows that the simulation of wheat production in China by CERES-Wheat tallies with the actual situation, and the crop model can be applied in China.(2) CERES-Wheat model is sensitive to temperature and precipitation, it can simulate the changes of wheat yield well when climate changes. By analyzing the sensitive of genetic parameters, we can identify the most sensitive parameter in wheat production based on the relative sensitivity. So as to provide a theoretical basis for determining the future direction of wheat cultivating.(3) Put the observed weather data, ERA data and corrected ERA data at Zhengzhou, Xuzhou, and other 11 stations into the crop model to simulate the wheat growth period and yield, and compare the simulated data with the observed. The results show that the approach of PRECIS coupled CERES-Wheat model is feasible, and can be used for impact assessment of climate change.(4) Evaluate the climate change under A2 and B2 scenarios in 2080s at Linfen, Linyi and other 9 stations. Compare the climate under A2 and B2 emissions scenarios in 2080s with baseline, the temperature rises obviously, and the temperature under A2 scenario rises more than that under B2 scenario. Solar radiation at some stations increases and others decreases, but the change trend under A2 and B2 scenarios is consistent. Precipitation shows an increasing trend except Guyuan and Huangyuan.(5) Climate change will lead to the wheat growing period ahead. The ahead days under A2 scenarios is longer than under B2 scenario, and the impact of climate change on winter wheat growth period is greater than that on spring wheat. If we only consider the climate factors, we can find that the wheat yield would reduce by 20% under A2 scenario and by 11% under B2 scenario on average. With CO2 fertilizer effect, wheat yield is significantly increased, and the yield is more than that in baseline at most stations. (6) Appropriately adjusting sowing time and cultivating and introducing new wheat varieties all can improve wheat yield effectively. For winter wheat, there is the best sowing time to get higher yield except in Xianyou; for spring wheat, sowed in advance appropriately can mitigate the adverse impact of climate change on wheat production, as well as in Xianyou. In the North introducing wheat varieties from the South and cultivating new wheat varieties in the South area can reduce the wheat yield reduction as climate change, and it is of great significance on improving wheat yield.