Decision Making Of Water And Fertilizer Supply For Greenhouse Tomato Based On Crop Phenotype Group

With to the development strategy of facility agriculture,modern agriculture is developing towards the direction of large-scale,specialization,automation,economization and high-yield production,which puts forward higher requirements for the accuracy,popularization and easy manipulation of facility crop irrigation,and greatly improves the utilization rate of water and fertilizer,yield and quality.Based on the Penman-Monteith model applied in the field of facility agriculture,this study explored the optimal irrigation amount and irrigation mode of greenhouse tomato through the feedback of the maximum growth rate of tomato phenotype group(plant height and stem straight),established the "environment phenotype" model by using related algorithms,and designed the drip irrigation system of water and fertilizer integration.The specific research contents and results are as follows:(1)The variation of evapotranspiration(ET0)during the whole growth period of Tomato in greenhouse was studied.From September 2019 to November 2020,the experiment was conducted in three batches(Experiment 1,2 and 3)in the research greenhouse of College of agricultural engineering,Shanxi Agricultural University,Taigu County,Jinzhong City,Shanxi Province(37°25′N and 112°34′E).The modified penman Monteith model was used to explore the variation of evapotranspiration of different varieties of Eggplant in different seasonal environments.The results showed that the average evapotranspiration in the whole growth period of Experiment 1,2 and 3 was 1.33 mm/d,2.57 mm/d and 2.28 mm/d;the variation rule of evapotranspiration of greenhouse tomato in winter and spring stubble was seedling stage >flowering stage > fruiting stage > harvest stage;the variation rule of Tomato in summer and autumn stubble was fruiting stage > flowering stage > seedling stage > harvest stage.The results showed that the evapotranspiration of tomato was the largest under the optimal cultivation conditions,better temperature and photosynthetic effective radiation,which provided data support for environmental management of facility agriculture and water and fertilizer irrigation.(2)To explore the best irrigation amount and irrigation mode of greenhouse tomato cultivation and management.Through the study of irrigation amount and irrigation mode,the feedback status of tomato phenotypic group growth was studied.The greenhouse tomato irrigation experiment W1(100%ET0),W2(80%ET0),W3(60%ET0)and irrigation mode experiment M1(radiation accumulation 50 KJ),M2(substrate humidity),M3(timing)were designed.The results showed that the growth rates of plant height and stem straight of W2 tomato were 6.23%,11.74%,12.53% and 3.01%,3.88%,5.83% respectively,and the growth rates of plant height and stem straight of M1 tomato were 6.23%,11.74%,13.64% and 3.01%,3.88%,5.83% respectively.Therefore,the best irrigation amount of greenhouse tomato is80%ET0,and the best irrigation mode is radiation accumulation,which provides theoretical guidance for water-saving irrigation of greenhouse tomato.(3)Establishment and validation of tomato phenotypic group(plant height and stem straight)model.The "environment phenotype" model was established based on the optimal irrigation amount and the phenotypic growth state of Tomato under irrigation mode.The phenotypic models of actual air pressure(P),environmental temperature(T),radiation volume(DTEP)and plant height were established by the essential nonlinear regression method.The phenotypic models of environmental temperature(T),radiation volume(DTEP)and stem straightness were established by the multiple quadratic regression method.The results showed that the fitting degree of plant height model(R2)was 0.9977,and the determination coefficient of measured value and simulated value was 0.965;the fitting degree of stem straight model(R2)was 0.9940,and the determination coefficient of measured value and simulated value was 0.9468.(4)According to the demand and design principle of water-saving irrigation in facility agriculture,an integrated drip irrigation system with low cost,high precision and uniform water and fertilizer mixture was designed based on ARM processor.The system is composed of three parts: water treatment system,automatic control system of water fertilizer integrated machine and water pipe network system.According to the working principle of system components,the pressure at the inlet and outlet of water fertilizer,water fertilizer mixing,water fertilizer flow rate,water fertilizer amount and the layout and internal diameter of water pipe network are regulated and determined.The water treatment system and human-computer interaction of the system greatly improve the intelligence of water quality and control,and improve the water and fertilizer utilization rate of facilities with the best irrigation quantity and mode supply strategy.