The Simulation Study On Adaptation Technology Of Climate Change On Grain Production In North China

With global warming, the climate in China has changed significantly; both the average state of climate change or changes in extreme climate events had a significant impact on grain production, and how to adapt climate change has become the hot topic of concern. Maize and wheat are the major food crops in north China, stable and high yield of which has a very important significance on the protection of national food security. Researching and evaluating adaptation technologies of grain production under climate change in north China has an important role on grain production in China.In this study, wheat and maize of the major food crops in north China as the research object, through linking the output of regional climate model PRECIS (Providing Regional Climate for Impacts Study), including 1961-1990(BASELINE), 2011-2040(2020s), 2041-2070(2050s), 2071-2100(2080s) under SRES A2 and B2 scenarios, and the core module of the DSSAT-CERES model, simulation of adaptation techniques and measures to the change of sowing date, variety introduction, improvement of irrigation conditions and so on was carried on. And climate change on crop yield was analyzed quantitatively, and the effect of the using adaptation technologies and measures was evaluated, therefore reference for decision making was provided to improve the adaptation ability of agriculture to climate change, and to make adaptation measures in agriculture.The main results of this research are as follows:(1) Through simulation in typical study site of north China by the CERES model, the testing result showed that the crop model had strong simulation ability, simulated flowering, maturity, yield and growing period had good correlation with the measured values , there was better consistency between simulated output of model in each site and observed values , and the error is within a reasonable range. It was suggested that the model had better applicability to maize and wheat production of north China and can be used to study the maize and wheat production under future climate change in north China.(2) Analyzed temperature and precipitation changes of regional 2080s relative to the baseline in time under the two scenarios of the future sessions, in addition, specifically analyzed the daily maximum temperature, minimum temperature and average precipitation in the daily weather data under future scenarios SRES A2 and B2, using PRECIS on Dunhua, Linyi, and other site. The results showed that regional differences of temperature and precipitation were relatively larger under the two future scenarios. In the A2 and B2 emission scenarios, each study site warmed by a big margin relative to the baseline period, and temperature increased more obviously in the A2 scenario rather than in the B2 scenario, also more obviously as time goes by. Meanwhile, the increasing rate was higher in daily minimum temperatures than in daily maximum temperature, precipitation had relatively large fluctuations, and distributed unevenly in the crop growth period.(3) Climate change had different effects on different crops in different regions, in addition, the impact of different periods were not same under different scenarios in the future. The simulation test results showed that in the current farming level and technical background, regardless of future climate change on wheat and maize production was beneficial or not, the volatility of the two crops were changing in future, and the change of yield volatility would increase the instability of the grain production.(4) Through adopting certain adaptation technologies or measures, such as agronomic measures considering in this study, adverse effects of climate change on wheat and maize production would reduce and beneficial effects would increase. The volatility of grain production should be paid more attention rather than the change of average grain yield. In particular, the volatility of grain production would be reduced adopting comprehensive adaptation technologies or measures, which would benefit the high and stable yield of grain production and conducive to the sustainable development of regional agriculture.(5) Crop model can be used for simulation of adaptation technologies by adjusting the corresponding parameters or module. The integrated adaptation technology with regional characteristics should be formulated combined with the actual situation of regional grain production, list of adaptation to climate change of regional grain production should be formulated, all of which would minimize the adverse effects of climate change and increase beneficial effects.