| In order to study the growth and development simulation and yield assessment of different water and nitrogen fertilizers under climate change of "Zhongmian 619" in southern Xinjiang by DSSAT-CROPGRO-Cotton model,the GLUE parameter package and "trial and error" method were combined to calibrate cotton variety parameters in Hetan using field test data in 2019.The field test data in2020 were used for verification.The calibrated model was used to simulate the growth period and yield of cotton under future climate change scenarios SSP1-2.6 and SSP5-8.5.Six different irrigation modes were set,and five different nitrogen application gradients were set under the optimal irrigation mode to obtain the optimal nitrogen application amount.The main research conclusions are as follows:(1)After adjusting GLUE parameters of DSSAT model,manual trial and error parameters were performed to obtain cotton variety parameters.The simulation results showed that the standard root mean square errors and ARE of the model for the 2019 cotton growth period,the simulated values of leaf area index and yield,and the measured values of field experiment were all less than 10%.The standard root-mean-square error and ARE of the simulated value of cotton growth period and yield in 2020 and the measured value of field test ARE both less than 10%.The root-mean-square error of the simulated value of leaf area index and the measured value of field test is 11.08% n RMSE and 9.4% average ARE,indicating that the overall accuracy of variety parameters is high.The calibrated model is suitable for cotton simulation in Hetan area.(2)Future climate change will shorten the biological period,which is not conducive to improving cotton yield in the study area.Under the SSP1-2.6 scenario,compared with the baseline,the average maturity time of cotton was shortened by 10 d,5d and 5d in 2040 s,2060s and 2080 s,respectively,and also reduced by10.35%,13.72% and 14.21%,respectively.Under the SSP5-8.5 scenario,the average maturity time of cotton was reduced by 10 D,5d and 5d,respectively.Compared with the baseline,the average maturity time of cotton was shortened by 9d,5d and 4d in the periods of 2040 s,2060s and 2080 s,and also decreased by19.19%,24.87% and 24.10%,respectively.Extreme weather leads to shorter crop growth periods,which leads to less dry matter accumulation,leading to lower yields.(3)Under SSP1-2.6 and SSP5-8.5,the yield under T5 irrigation could reach the maximum.The yield of cotton increases with the increase of irrigation,but the yield decreases when the amount of irrigation reaches a certain value.Five nitrogen gradients were set under the T5 irrigation scheme,and the experiment showed that the maximum yield could be reached under the N4 scheme,and the average yield under the N4 scheme was the highest with the nitrogen application of 275kg/ha.The yield of cotton increased with the increase of N application,but the yield decreased when N application reached a certain value.Under SSP1-2.6 and SSP5-8.5 scenarios,the baseline yield was compared with the yield after optimal irrigation and nitrogen application,and the optimal yield was obtained.Under SSP1-2.6 scenario,the highest yield could reach 6135kg/ha and the average yield could reach 4845.12kg/ha.This paper provides theoretical guidance for optimal management of cotton water nitrogen fertilizer in southern Xinjiang under climate change. |
