Effect Of Irrigation Water Low Limit On Tomato Yield And Water Use Efficiency Of Tomato Under Drip Irrigation

In order to optimize and innovate irrigation forms and irrigation methods,and alleviate the shortage of agricultural irrigation water in my country,water-saving irrigation technologies have been widely used to increase the utilization rate of irrigation water resources.This study mainly used the two-year greenhouse tomato test data and the CROPGRO-Tomato model to simulate the growth and development process and yield of greenhouse tomatoes in Hongyu Vegetable Planting Cooperative in Xiqing District,Tianjin City.Using the greenhouse tomato test data of three irrigation treatments(60%θf,70%θf,80%θf,θf is the field water holding capacity)from 2020 to 2021 to analyze and correct the parameters of 14 tomato crop varieties in the CROPGRO-Tomato model,and compare them Fitting degree and error analysis of field measured data and model simulation data,and three sets of parameter schemes of greenhouse tomato varieties suitable for Tianjin area are obtained.Then the model was verified and analyzed based on the experimental data of empirical irrigation treatment of greenhouse tomatoes from 2019 to 2020.Finally,the debugged model was used to set seven irrigation water limit treatments(50%θf,55%θf,60%θf,65%θf,70%θf,75%θf,80%θf),predict and simulate tomato yield and tomato water consumption.By analyzing the effects of different irrigation limits under drip irrigation conditions on greenhouse tomato yield and water use efficiency,it provides theoretical support and technical support for the precise production of greenhouse tomatoes in Tianjin and water saving and efficiency.The main conclusions of this study are:(1)The parameter results of Plan 1 are most suitable for the growth process of greenhouse tomatoes in Tianjin.The ARE value of all treatments from 2020 to 2021 is 2.87%,and the n RMSE value is 3.91%.Among them,the parameter FL-SH has a greater impact on the simulation accuracy of the model,and the simulation accuracy of the model is obviously not as good as that when the crop is full of water.Tomato phenology has little effect on the limit level of irrigation water,that is,water stress.For tomato growth indicators,the higher the irrigation water limit,the greater the irrigation volume,the more luxuriant the above-ground part grows,the greater the dry matter quality,and the better the crop growth.(2)In the stage of model verification using greenhouse tomato test data from 2019 to2020,the simulation verification results have high accuracy,with an ARE value of 5.12%and an n RMSE of 8.99%.(3)In the stage of predicting tomato yield by setting seven different irrigation levels with the parameters of the calibrated plan 1,the optimal irrigation limit range is65%θf～70%θf,and the predicted tomato yield reaches 63938kg/hm~2～68200kg/hm~2.