Simulation Of Climate Change On Conservation Tillage Of Winter Wheat In Western Region Of Henan Province

Drought, soil erosion and soil degradation are main factors that restricting the agricultural development on the Loess Plateau dry-land in the western region of Henan Province for a long time. Looking for a breakthrough, the researchers reform and optimize the conservation tillage techniques to maintain the sustainable development of agriculture in the area, enhance the utilization efficiency of limited precipitation and improve the soil environment. Then, the encouraging consequence is emerging. In recent years, resulting from the high concentration of green house gases, the global warming has been recognized in all over the world. The impact of climate change on crop growth, economic development and environment protection are more and more concerned by both scholars and officers. The climate condition becomes the primary factor effecting crop growth and development, especially in the agricultural regions of dry rain-fed, such as the West Henan Loess hilly region where the crop yield mostly depends on the weather. Therefore, it is theoretically and practically significant to study on the effect of conservation tillage with the crop model under future climate scenarios in this region.Based on the characteristics of loess hilly region, this study used the IPCC SRES green house gases emission scenarios A2 and B2 as simulation, combining with the climate model and weather generator, to provide long term future daily weather data. Aiming at studying on the conservation tillage of winter wheat in this region under future climate scenarios, we applied the DSSAT crop model to simulate growth and development process and production of winter wheat that was managed by four kinds of conservation tillages. In addition, we also evaluated the effect of conservation tillage in the future. The main achievements of this study are as follows: 1) Analyzed the regional suitability of DSSAT model and established parameter system of model. We established DSSAT model database and validated it, the DSSAT model verification results showed good suitability in winter wheat growth and development and soil moisture simulations in the western region of Henan province.2) According to the future climate prediction, the CO2 concentration and the average temperature and precipitation will increase under A2 and B2 climate scenarios in 2020,2050 and 2080 in the western region of Henan. And the winter wheat growth will be improved in the future climate condition.3) The model simulation indicates that the yield of winter wheat will increase, irrelevant to the fertilizer effect of CO2 under the A2 and B2 climate scenarios in this region. So, we believe that the future temperature change hasn't shown obvious negative effect on the growth of winter wheat and the yield of winter wheat will increase because of the accordingly increased precipitation.4) Under the climate change situation, the model prediction results show that the growth period of winter wheat, managing with four tillage-treatments, is not sensitive to the change of CO2 concentration. Under four kinds of tillage-treatments, soil evapotranspiration and water productivity are elevated. In the future climate conditions, biological yield of winter wheat will increase, along with the rise of CO2 concentration.5) In the future climate conditions, the precipitation, evapotranspiration, cropland water consumption and crop yields will mount in the western region of Henan; the crop yield increase in this arid and semi-arid area will alleviate the pressure of the increasing population, and gradually improve the food-shortage situation. Relatively, using zero tillage with cover-treatment measures of winter wheat, one of the four tillage-treatments, we can obtain the best growth rate of simulated yield and its response sensitivity to climate change is maximum.Generally, our study demonstrates that in order to avoid the harm on the winter wheat growth from the warm temperature, and rationally and effectively take the advantage of precipitation under the future climate conditions, the most feasible conservation tillage model should be the zero tillage with cover-treatment measures in the western region of Henan.