The Effects And Adaptive Technology Of Climate Change On Grain Production And Net Greenhouse Effect In North China

Agriculture is one of the most sensitive sectors affected by climate change.It is of great significance to assess the impact of climate change on food production and sustainable development in the North China Plain,as an important food producing area in China,and then put forward countermeasures to ensure food security in China.However,due to the uncertainty of climate change and the complexity of its impact on agriculture,it is difficult to conduct research using only conventional field monitoring methods,and it is also difficult to formulate targeted countermeasures.Based on this,the method of combining field monitoring and biogeochemical model were used in this paper.The data of greenhouse gas emission of winter wheat summer maize rotation system in Huantai,Shandong and Ye County,Henan were obtained to construct and validate the DNDC model,and then,The model was used to simulate the crop yield,N₂O emission and Based on the influence of soil organic carbon.Finally,it suggested to discuss the optimal management measures which can not only guarantee the crop yields but also reduce the net greenhouse effect under the influence of climate change,so as to guide the agricultural production practice and provide scientific basis for promoting the green development of agriculture.The main research results are as follows:?1?The DNDC model is more accurate in simulating the crop yield,total N₂O emissions and SOC,among them,the simulation results of crop yield and total N₂O emissions in Shandong are good,the fitting goodness R² is above 0.80,and the model efficiency NSE is also above 0.57.At the same time the SOC is more consistent under different treatment,with the goodness of fit R² is above 0.73,and the model efficiency NSE is above 0.65.It shows that the DNDC model has the ability to accurately simulate and evaluate the yield,N₂O and SOC of winter wheat-summer corn rotation system.?2?Climate change has a great impact on crop annual yield and net greenhouse effect.Compared with the traditional production,under the two scenarios of temperature reduction of 3?and rainfall reduction of 30%,the crop yield decreased by 11.10%and 7.59%.When the temperature increases by3?,the crop yield was decreased by 4.37%,and net greenhouse gas emissions was increased by 32.85%;when the rainfall increases by 30%,the crops was increased by 3.87%,and net greenhouse gas emissions was increased by 10.75%;when the temperature changes by a small margin?increase or decrease by 1and 2??,it is not significant impact on crop yield,but the net greenhouse effect will decrease when the temperature decreases,and vice versa the net greenhouse effect will increase.Rainfall?reduction of 10%and 20%?will cause the reduction of crop yield and net greenhouse effect.Conversely,it will increase crop yield and net greenhouse effect.?3?Different management measures have different effects on climate change.Under the situation of3?decrease in average temperature,the net greenhouse gas emissions of 26.60%and 28.46%can be reduced by changing the planting time of crops and cold resistant varieties.When the average temperature is increased by 3?,all measures can't stabilize the yield.Only the integrated measures of drought resistance and water and fertilizer of improved varieties can minimize the negative impact of the yield?the yield reduction rate is only 2.56%?.When the average rainfall in the same year is reduced by 30%,the integrated management measures of water and fertilizer and the drought resistant varieties can stabilize the production?the integrated measures of water and fertilizer can increase the production by 2.72%?,reduce the net greenhouse gas emissions of 8.39%and 10.96%;when the average rainfall is increased by30%,all measures can increase the production,but the straw returning measures can increase the production by 3.87%and reduce the net greenhouse gas emissions of 357.19%,which has a higher environmental effect.In general,DNDC model has the ability to accurately assess the impact of climate change on the yield,N₂O emissions and SOC on wheat maize rotation system.The scenario of 3?temperature and 30%rainfall change had the most significant effect on crop yield and net greenhouse effect.Improving crop varieties,changing crop sowing time,adopting integrated measures of water and fertilizer and all straw returning to the field can not only ensure crop yield,but also reduce N₂O emissions and increase soil organic carbon in varying degrees,so as to reduce net greenhouse gas emissions,which is an effective measure to cope with climate change.In the future,we should strengthen the research on the impact of climate change on agricultural production in order to propose targeted adaptation measures.