Coupling Model Of Water And Fertilizer For High Yield Potential Of Rice Under Future Climate Change

Since the middle and late 20th century,climate change has been a hot topic all over the world.With the change of global climate and the change of natural climate elements,the growth and development process of crops will also change.Similar to climate change,the regulation of water and fertilizer also significantly affects rice yield.The difference is that the former is uncontrollable,while the latter is controllable.In order to explore the effects of future climate change on rice yield under different coupling conditions of water and fertilizer,addressing sustainable development of rice production in the context of global climate change,rice planting experiments were conducted in 2020 and 2021 at Hubei Irrigation Experimental Central Station.Plant height,tiller number,chlorophyll SPAD value,leaf area index,nitrogen distribution and utilization,dry matter and yield of rice at different growth stages were analyzed by four treatments,namely,inundation irrigation(W1),intermittent irrigation(W2)and traditional fertilizer(N1)and slow-release fertilizer(N2).ORYZA2000(v3)model is calibrated and verified by using two years’test data,and meteorological data under Can ESM5climate models SSP1-2.6,SSP2-4.5 and SSP5-8.5 are downscaled by SDSM model.By forecasting the meteorological data in the middle(2045-2054)and the end(2090-2099)of the21st century,and combining ORYZA2000(v3)to simulate the rice yield in Zhanghe Irrigation District under different coupling conditions of water and fertilizer under different climate scenarios in the future,the results of rice yield changes caused by different coupling conditions of water and fertilizer were compared and analyzed.The main conclusions are as follows:(1)From the perspective of rice yield in the two-year field experiment,the rice yield under the W1 and W2 modes in 2020 was 54.42%and 30.42%higher than that under the N1condition,respectively.In the W1 and W2 models in 2021,the rice yield under N2 and N1conditions was 21.23%and 11.95%higher,respectively.From the perspective of rice physiology and ecology,the physiological and ecological performances under N2 condition were better than those under N1 condition,and the rice yield under slow-release fertilizer N2condition was significantly higher than that under traditional fertilizer N1 condition,indicating that slow-release fertilizer was beneficial to promote the growth and development of rice and the yield.(2)In ORYZA simulation results,the correlation coefficients(R~2)of rice indexes(above-ground biomass,panicle biomass,stem biomass,leaf biomass,leaf area index,yield)ranged from 0.909 to 0.991,and the relative errors(RMSE_n)of various simulation indexes ranged from 6.30%to 27.25%.In the SDSM simulation results,the correlation coefficients(R~2)of each meteorological element index(maximum temperature,minimum temperature,wind speed,rainfall,sunshine duration,water vapor pressure)ranged from 0.779 to 0.999.The simulation results of ORYZA and SDSM models were good,which can be used as a tool to predict the future meteorology and rice yield in Zhanghe Irrigation District.(3)With the advance of time and the increase of radiation intensity emission,the average level of a number of meteorological indicators is significantly higher than the average level of the historical period.In the future climate of Zhanghe Irrigation District,the temperature will increase by 0.94～4.66℃and the annual precipitation will increase by282.2～1314.5mm on average under different scenarios,and the change is the least under SSP1-2.6 scenario.Under the SSP5-8.5 scenario,the temperature rises the fastest and the probability of extreme climate is the highest.Compared with the baseline period(2000-2005),under the future scenarios of SSP1-2.6,SSP2-4.5 and SSP5-8.5,the average rice yield reduction in the middle of the 21st century was 23.05 kg/hm~2,307.55 kg/hm~2 and 605.63kg/hm~2.At the end of the 21st century,the average yield reduction of rice was 281.65 kg/hm~2,465.03 kg/hm~2 and 890.83 kg/hm~2.With the increase of time and situation,reduce the difference between different sewage sludge processing production.By comprehensive comparison,it is concluded that the combined pattern of water and fertilizer for medium rice in Zhanghe Irrigation District in the middle of 21st century under the condition of future climate change is the inundation slow-release fertilizer W1N2 treatment.In the late 21st century,under the condition of future climate change,the coupling model of water and fertilizer for medium rice in Zhanghe Irrigation District was W1N1,which was the highest yield.The popularization of the above two models could alleviate the adverse effects of climate change on rice yield in Zhanghe Irrigation District in the future.