Research Of Crop Water Production Function For Greenhouse Tomato Based On CROPGRO-Tomato Model In The Northeast Cold Areas

In order to evaluate the suitability of DSSAT model in the simulation of tomato growth,this study applied the DSSAT-CROPGRO-Tomato model to simulate the growth and yield of tomato under different irrigation levels in greenhouse in Northeast cold region of China.The optimal plan was also determined for the estimation of genetic parameters and model verification.Irrigation upper limit of whole growth season was set as field capacity,while the upper limit was 50%(W1),60%(W2),70%(W3),and 80% of field capacity(CK).There were a total of 4 treatments with 3 replicates for each.The experimental data were used for model calibration and verification.The DSSAT-GLUE,a program package for parameter estimation in DSSAT,was used to estimate the relevant genetic coefficients.Then the result were compared for the discrepancies between corresponding simulated and observed values of phenological phase,canopy height,tops dry matter weight,tomato fresh weight,leaf area index(LAI),and soil moisture so as to determine the accuracy of CROPGRO-Tomato model to simulate the agro-ecological processes of tomato farming system in greenhouse.The results show:(1)The genetic parameters of tomato PODUR(final fruit under optimal conditions required by the load time estimation of photothermal)has great variability,the variation coefficient was 11.45%,the indoor temperature,irrigation management measures and greenhouse environment influence.(2)Using crop growth period full irrigation treatment data to calibrate the model,and select the remaining irrigation treatment data to verify the model,the overall ARE and nRMSE values are only 8.66% and 10.46%,and the accuracy of the model simulation is higher than other schemes.(3)The dynamic analysis of tomato LAI and soil water content showed that the higher the irrigation level was,the higher the model simulation accuracy was.The model could not accurately describe the LAI and soil water content of greenhouse tomato caused by different irrigation levels under high temperature and radiation levels.(4)The cross-validation results showed that the CROPGRO-Tomato model was used to simulate the growth process of greenhouse tomato under different irrigation levels for two years.The overall error ranged from 10.5% to 12.5%.(5)Tomato greenhouse experiment Jensen,Minhas and Stewart model water deficit sensitivity index from high to low in order for the fruit stage,harvest stage,flowering and fruiting stage,seedling stage,while the Blank model results for the fruit stage,harvest stage,seedling stage,flowering and fruiting stage;two tomato simulation tests Jensen,Blank,Stewart and Minhas water model stress sensitivity index from high to low in order for the fruit stage,harvest stage,flowering and fruiting stage,seedling stage,and the measured data derived results are similar.Based on the scenario simulation of the CROPGRO-Tomato model,Reduce the irrigation threshold at the seedling stage and flowering and fruit setting stage of CK to 50% of the field water holding rate can increase production by 3.56% and save 14.91% of irrigation volume at the same time.