Analysis Of Maize Yield Potential And Optimization Of Sowing Date And Density In Hubei Based On DSSAT Model

Maize planting systems in Hubei province are complex,with long sowing periods available,and different sowing periods have significant effects on the configuration of climatic factors at different stages,which in turn can affect the formation of maize yield.Moreover,there is a lack of research on the effect of sowing period regulation to achieve disaster avoidance and yield in Hubei Province,and whether the desirable sowing period has changed in the context of global warming needs to be explored.In this study,we analyzed the response of maize yield to variety,density,and sowing period using a multi-year multi-point experiment from 2017-2022,and then calibrated and validated the DSSAT model by selecting three different types of maize varieties,based on day-by-day meteorological data from 2001-2017meteorological observation stations at three experimental sites in the maize production area of the Jianghan Plain in Hubei Province,and setting 10 sowing periods and five planting densities,and the DSSAT model was used to simulate the yield,biomass and fertility changes of different maize varieties types at different sowing periods and densities,and the changes of climate resources within each fertility stage,to explore the suitable sowing periods and densities,and to provide a scientific basis for the rational use of climate resources and the full exploitation of maize production potential.The main results are as follows:1.multi-year multi-location trials integrated analysis showed that sowing period and planting density density had a significant effect on corn yield.Both spring and summer sown maize yields increased and then decreased with planting density;spring sown maize yield was 45.35%higher than summer sown maize yield.Different variety types of maize responded differently to sowing period and planting density under different conditions;under spring sowing conditions,compact maize had the highest effect of increasing density and yield under high density planting pattern;under summer sowing conditions,variety types had no significant effect on increasing density and yield.2.The integrated analysis of multi-location trials over many years showed that climatic factors had a significant effect on maize yield,and at the VT-R3 stage,injury cumulative temperature had the greatest effect on yield,followed by average daily temperature,then by rainfall,and finally by solar radiation.3.The model was calibrated and validated by field data of spring and summer sown maize.According to the calibration and validation results between the simulated and measured values of phenological period,seed yield,and aboveground biomass,the localization of the model was evaluated well,and the DSSAT model could effectively simulate the growth and development of maize in the region.4.The analysis based on DSSAT model showed that with the delay of sowing,the number of days of sowing-maturing fertility period was subsequently shortened,and the range of shortening was from 14 to 17 days;the number of days of duration of sowing-maturing fertility period first decreased and then increased,and the range of variation was from 2 to 18 days.5.The analysis based on DSSAT model showed that the yield and biomass of maize increased with the increase of planting density,and the number of ears and 100grains weight decreased with the increase of planting density in the same sowing period;in Huanggang and Jingmen test areas,the yield,biomass,100 grains weight and number of ears of maize decreased with the delay of sowing period,and the yield of maize decreased by 40.79%and 9.89%with the delay of sowing period in the two areas,respectively.In Xiangyang trial area,yield and biomass increased with delayed sowing and 100 grain weight for number of grains per ear decreased,and maize yield increased by 48.13%.6.The sowing date had a significant effect on the coefficient of variation(CV)and yield sustainability index(SKI).Yield stability and sustainability were best in Huanggang and Jingmen test areas sown from April 1 to April 10 each year;and in Xiangyang test area sown on May 20.7.Based on model analysis,it was shown that in Huanggang and Jingmen test areas,rainfall was 515-682 mm,solar radiation was 2036-2082 MJ/m2,active cumulative temperature was 2762-2816°C,and average daily temperature was27.5-27.8°C at 30 d after male extraction for the highest yield;in Xiangyang test area,rainfall was 403 mm,solar radiation was 1792 MJ/m~2,active cumulative temperature2691℃,and the highest yield was achieved with the average daily temperature of24.2℃after male extraction.In summary,different regions should choose the appropriate sowing period according to the local natural conditions.In Huanggang and Jingmen,the sowing period was from April 1 to 10,and in Xiangyang,the sowing period was from May 20to 30.The planting density of 120,000 plants/hm~2can improve the growth environment among maize populations and make full use of climatic resources to achieve high and stable yields.