Simulation Study On Water And Fertilizer Coupling Of Winter Wheat Based On DSSAT Model

Water and fertilizer promote each other and restrict each other.They are two important factors and main control methods in agricultural production.They are also the main factors that cause fluctuations in winter wheat output.I In Liao Cheng,since the precipitation is mainly concentrated in the summer,winter wheat growth is seriously irrigated.Therefore,it is of great significance to study the coupling of water and fertilizer for winter wheat in this area.In this study,there were winter wheat for research objects,and different water fertilizer treatment measures were carried out.Different water fertilizer measures on winter wheat growth were analyzed,and the meteorological,farmland observations and management information between 2015-2020 were used to construct a business in Liao Cheng.Mountain Irrigation Test Station DSSAT Winter Wheat Growth Model,the growth of winter wheat in different water fertilizers,the main results are as follows:(1)For winter wheat,under medium and high irrigation levels,the leaf area index and above-ground dry matter increase with the increase of fertilization.However,under low irrigation level,the increase of fertilization will affect the crop leaf area and above-ground dry matter.Produce an inhibitory effect.(2)In the process of model simulation,the genetic parameters of the winter wheat varieties contained in the DSSAT model are first determined,and the value ranges of the corresponding parameters are determined,and then the simulation and simulation verification analysis are performed.The DSSAT model is based on the local variety Tai Nong No.18 in 2015-2020.The normalized root mean square error of the current year’s output simulation during the growth period was all less than 7%.The leaf area index is less than 17%,the above-ground dry matter is less than 12%,and the growth period is less than 5 days,indicating that the model has a good simulation effect in this region.(3)Based on the local field data,different water and nitrogen measures in line with local fertilization and irrigation habits were set and simulated.The winter wheat yield of each treatment increased with the increase of nitrogen application and irrigation volume.When the irrigation quota reached 80 mm,apply When the nitrogen amount reached 220 kg/hm~2,the irrigation amount and nitrogen application rate continued to be increased,and the yield increase effect was not significant.(4)According to the application of the DSSAT model,the strategy of various irrigation levels during the growth and development season of winter wheat was simulated and the following results were obtained:Under the same farming method,irrigation method and nutrient supply conditions,various irrigation measures It has a significant effect on the yield and water use efficiency of winter wheat.The best irrigation strategy for each irrigation frequency is three waters(overwintering+jointing+heading water)>two waters(joining+grouting water)>one water(joining water)>no watering.The order of the best measures for water use efficiency is watering two waters(joining+grouting water)>watering one water(joining water)>watering three waters(joining+heading+grouting water)>no watering,and secondly,the whole winter wheat growth and development stage Jointing water should be watered most.The three years of 2009-2010,2014-2015,2017-2018 were selected as dry years,wet years and peace years to carry out the research,and it was concluded that the water saving effect of watering and jointing in wet years was good,and the jointing and grouting in normal water years were good.Water was the best water and fertilizer plan of the year.Water saving in dry years,heading water and grouting water yield and water use efficiency were the best.