Study On Adjustment Strategy Of Rice Production Adaptation To Climate Change Based On ORYZA20000 Model In Shenyang

Rice is an important food crop in China.Northeast China is one of the main rice planting areas in China.In recent years,farmers have gradually increased the amount of fertilizer applied.However,excessive application of nitrogen fertilizer will cause a series of ecological and environmental problems.There are major threats to production and sustainable agricultural development.This study uses the ORYZA2000 model to explore suitable fertilization measures in Shenyang,and based on this model to evaluate changes in rice yield under future climate conditions,and proposes adaptive adjustment schemes to provide a reference for the adjustment of the agricultural industrial structure and to ensure sustainable agricultural development.The ORYZA2000 rice model is calibrated based on actual field data.The model simulate 9036,9035,9023,Yanfeng 47,Shennong 263,Tiejing 11,Tiejing 12 biomass and yield of 7 rice varieties in Shenyang,and performe rice Model validation.The revised ORYZA2000 model is used to explore the effects of different fertilization on rice yield,carbon efficiency,and nitrogen use efficiency in Shenyang in the past,and then a suitable fertilization plan for Shenyang is recommended.Using the revised rice model combined with CMIP5 future climate model data,the future changes in the yield of seven rice varieties in Shenyang 9036,9035,9023,Yanfeng 47,Shennong 263,Tiejing 11,and Tiejing 12 are analyzed and are changing.Investigating the adaptive strategies in three aspects: sowing date,total amount of nitrogen application and variety,the conclusions are as follows:1.The ORYZA2000 rice model has the best simulation effect on the above-ground total biomass.The stem biomass simulation effect of most varieties is slightly worse than that of panicle biomass,and the simulation effect of green leaf biomass is the worst.The model can simulate the variety of each variety better Leaf area index and yield can be used to predict future rice yield in Shenyang.2.Through the analysis of the effects of nitrogen fertilizer application rate and basal tiller fertilizer(early stage)and ear fertilizer(late stage)nitrogen application ratio on rice yield,carbon efficiency and nitrogen fertilizer utilization efficiency,it is found that rice yield increased with the increase of nitrogen application rate.However,when the amount of nitrogen apply reached a certain level,the increase in yield is not obvious.While the nitrogen fertilizer utilization efficiency continue to decrease with the increase of nitrogen application,the change of carbon efficiency show a trend of increasing first and then decreasing.Suitable fertilization management schemes for different varieties: 9035,Shennong 263,the suitable nitrogen application rate is 180kg/ha,9023,Yanfeng 47,the suitable nitrogen application rate is 210kg/ha,and the iron application rates of Tiejing 12 and Tiejing 11 are: 120 kg / ha,the suitable fertilization ratio of all varieties in the early and late period is 4: 6.3.Through the combination of the ORYZA2000 rice model and the future climate model,it is explored that in the future climate scenario,the middle-maturing late varieties(9036)show a yield increase trend,while the middle-maturing varieties(9035)and mid-mature varieties are early(9023)There will be a tendency to reduce yield,and the growth periods of rice varieties at different maturity periods will be shortened.For other rice varieties,the yields of Shennong 263,Yanfeng 47,Tiejing 12,and Tiejing 11 will be all reduced in yield compared with the base year(1991-2000),and the number of days in the growth period will be shortened.The average rice growth period will be shortened by 2 to 3 weeks.At the end of the 21 st century,the yield reduction of rice will be more obvious than that in the middle of the 21 st century,and the growth period will be shortened to a greater extent.4.Comprehensively considering the adjustment of the sowing date,the optimization of the total amount of nitrogen fertilizer application and the optimization of variety maturity,two adjustment strategies will be obtained: the sowing date of the 9035 variety will be delayed by 30 days,and the nitrogen application rate is 280kg/ha;the sowing date of the 9036 variety will be delayed by 30 days,The nitrogen application rate is 240kg/ha.Both of these strategies are conducive to the increase of rice production in Shenyang in the future climatic conditions,and the two varieties have shown an increase in yield compared to the baseline period,of which 9036 varieties have an increased yield of 11.09% ~ 13.88%.After other varieties have been adaptively adjusted,they will continue to show a trend of reduced production under future climatic conditions.Therefore,in the future,the suitable varieties for planting in Shenyang are 9035 and 9036,which are matured later than the current main varieties.