Study On Irrigation Effect Of Greenhouse Tomato Soil Cultivation Based On Advanced Decision Irrigation Model

Accurate decision making is the basis of intelligent irrigation.Advanced decision irrigation model is an irrigation decision model built on the basis of tomato substrate cultivation weighing method.This model takes hour as step length,introduces the theory of transpiration delay effect,and accurately predicts the current crop water requirement through the actual crop leaf area,photosynthetically active radiation and temperature and humidity in the greenhouse 1 h ago.In order to verify the scientific nature of the advanced decision irrigation model in soil cultivation and to find the optimal irrigation volume by applying the advanced decision irrigation model in soil cultivation.In this paper,the irrigation rate calculated by Penman-Monteith model was used as control（PM treatment）,and three different irrigation rates（0.8 ET,1.0 ET,1.2 ET）based on the advanced decision irrigation model were set in the flowering and fruit setting stage and fruit expanding stage of greenhouse tomatoes.The effects of different irrigation treatments on the biomass,photosynthetic index,yield,quality,water use efficiency and soil water content of greenhouse tomato were compared between the advanced decision irrigation model and the PM model.The entropy-Topsis comprehensive analysis method was used to evaluate the different treatments,and the optimal irrigation treatment based on the advanced decision irrigation model was screened.In order to find the optimal irrigation frequency of the application of the advanced decision irrigation model to soil cultivation,based on the research basis of the optimal irrigation volume of the advanced decision irrigation model,three different irrigation frequencies were set in the whole growth period of tomato soil cultivation（one irrigation in 4 days,one irrigation in 5 days and one irrigation in 6 days）.The effects of different irrigation frequencies of the optimal irrigation volume based on the advanced decision irrigation model on the biomass,photosynthetic index,yield,quality and water use efficiency of greenhouse tomato were studied,and the optimal irrigation frequency of the advanced decision irrigation model for soil cultivation was obtained through the comprehensive evaluation method.In order to verify the applicability of the advanced decision irrigation model in different tomato varieties,three tomato varieties（Jinpeng 2023,Jinpeng No.10,Tianxin No.2）were selected for variety comparison experiments,and the effects of the advanced decision irrigation model on the yield,quality and water use efficiency of different tomato varieties were studied.The applicability of advanced decision irrigation model to different tomato varieties was evaluated by comprehensive analysis.The main findings are as follows:（1）According to the comprehensive analysis of entropy weight and TOPSIS,T2-3（1.0ET irrigation at flowering stage,1.2 ET irrigation at fruit expansion stage）under the advanced decision irrigation model ranked the first place;PM treatment（PM model irrigation）ranked the eighth place for autumn crop tomatoes and the 10th place for spring crop tomatoes.Based on the advanced decision irrigation model,three different irrigation frequency treatments were ranked as T5（irrigation once in 5 days）>T6（irrigation once in 6 days）>T4（irrigation once in 4 days）.Based on the advanced decision irrigation model,the comprehensive indexes of three different tomato varieties were ranked as T7（Jinpeng 2023）>T9（Tianxin 2）>T8（Jinpeng 10）.（2）Compared with PM model,soil moisture content fluctuates less when using the advanced decision irrigation model,and the accuracy can be improved when using the advanced decision irrigation model for irrigation in rainy days.（3）In spring crop greenhouse tomato cultivation,advance decision irrigation model T2-3 treatment is the best.Plant height,stem diameter,leaf area size,net photosynthetic rate,stomatal conductance,chlorophyll content,lycopene content,vitamin C content,reducing sugar content and water use efficiency of T2-3 were significantly increased compared with the control.Respiration rate,intercellular CO₂ concentration and carotenoid content were significantly decreased compared with the control.There was no significant difference between yield and sugar-acid ratio.（4）In the greenhouse tomato cultivation of autumn crop,the advanced decision irrigation model T2-3 treatment was the best.Stem diameter,leaf area size,net photosynthetic rate,stomatal conductance,chlorophyll content,carotenoid content,yield,water use efficiency,lycopene content,vitamin C content,sugar-acid ratio and reducing sugar content of T2-3 were significantly increased compared with the control.Transpiration rate was significantly lower than that of the control.There were no significant differences in plant height,intercellular CO₂concentration and sugar-acid ratio.（5）In the experiments of different irrigation frequencies based on the optimal irrigation volume of the advanced decision irrigation model,T5 treatment was the best.The plant height,dry and fresh weight per plant,net photosynthetic rate,intercellular CO₂ concentration and vitamin C content of T5 were significantly higher than those of T4 and T6.There were no significant differences in transpiration rate,stomatal conductance,chlorophyll content,carotenoid content,lycopene content,soluble total sugar content and reducing sugar content between T5 treatment and T4.There were no significant differences in yield,water use efficiency and carotenoid content between T5 treatment and T6 treatment.6.In the variety comparison experiment of the advanced decision irrigation model,the yield and vitamin C content of optimal treatment T7 were significantly increased compared with T8,and the lycopene content was significantly increased compared with T9;There were no significant differences in lycopene content,soluble sugar content,reducing sugar content and water use efficiency between T7 and T8.The yield,vitamin C content,reducing sugar content and water use efficiency of T7 were not significantly different from that of T9.（6）In the experiment of varieties comparison of advanced decision irrigation model,T7treatment was the best.Compared with T8,the yield and vitamin C content of T7 and lycopene content of T9 were significantly increased.There were no significant differences in lycopene content,soluble sugar content,reducing sugar content and water use efficiency between T7and T8.The yield,vitamin C content,reducing sugar content and water use efficiency of T7were not significantly different from that of T9.In conclusion,no matter in spring or autumn,the advanced decision irrigation model has high irrigation accuracy in soil cultivation.The optimal irrigation quantity was 1.0 ET irrigation at flowering stage and 1.2 ET irrigation at fruit expansion stage.Based on the optimal irrigation quantity of the advanced decision irrigation model,the optimal irrigation frequency was irrigation once every 5 days during the whole growth period of tomato.The advanced decision irrigation model has good adaptability to the three common tomato cultivars,among which Jinpeng 2023 has the best response to the advanced decision irrigation model.