Study On Water Transport, Physiology Drip And Irrigation Control System Of Strawberry Elevated Substrate Cultivation

Elevated cultivation is a new type of facility cultivation model, with the substrate as the cultivation medium, and drip irrigation as the irrigation mode, in the facilities of strawberry cultivation has been a certain extent of promotion. But the water management of the elevated cultivation is still relatively extensive, water waste is more serious.To solve this problem, The water distribution characteristics of the mixed media of strawberry elevated cultivation under drip irrigation and different irrigation lower limit on Physiological Indexes of strawberry impact test were carried out using a set of self-buit greenhouse strawberry elevated cultivation test rig.In order to reduce the waste of water in strawberry production, a set of test bench was built to study the water distribution characteristics of the mixed media of the strawberry elevated cultivation under the condition of drip irrigation. In the end, on the basis of the above, a set of monitoring and control system for greenhouse cultivation was designed and developed, which provides a scientific basis for the guidance of the precision irrigation of the elevated strawberry.The main research contents and results are as follows:(1)Study on water transport characteristics of elevated substrate cultureMonitoring the water content of the substrate of the elevated substrate culture trough, survey the Variation characteristics of water content in horizontal direction and vertical direction of observation section.The research show that: drip irrigation volume for strawberry should not be higher than 90 ml per plant in elevated cultivation, The first 20 min is the peak of water diffusion after the end of drip irrigation, later, water diffusion rate slowed down, and the substrate moisture tends to be stable when 60min; a faster diffusion rate of the water level, greater final diffusion distance, and larger wetting radius emerge as the initial water content becomes greater. The first 20 min internal matrix horizontal diffusion distance increment were 3.7cm, 3.8cm, 4.0cm respectively, the final horizontal diffusion distance increment were 6.61cm、6.72cm、6.90 cm respectively. there is no significant difference between the three treatment; The substrate water content at the 10 cm depth of the same distance from the drip irrigation emitter was higher than that of the 5cm;after the end of drip irrigation,the maximum difference of the moisture content of the substrate in the groove is 36%, and the value is 24%.when the flow rate is 0.5L/h, the cultivation groove matrix water rate of which was more uniform. In summary, strawberry elevated cultivation, according to strawberry water requirement rules to determine suitable lower limit of irrigation. In the actual production, it is suitable for high frequency irrigation, drip irrigation volume for strawberry should not be higher than 90 ml per plant. It is better to select moisture monitoring point near the root of strawberry and 10 cm is a good depth to monitor water content of matrix.(2) Effects of substrate moisture on physiological characteristics of StrawberryThe matrix moisture sensor probe was inserted in the elevated culture substrate groove,monitored the changes of physiological and ecological indexes of strawberry under gradual drought, designed four different irrigation lower limit, study on the changes of physiological and ecological indexes of strawberry before and after rewateringso as to determine the strawberry elevated cultivation best drip irrigation lower limit.The results showed that photosynthetic parameters of Pn, Trand Gs, leaf water potential, chlorophyll fluorescence parameters Fv/Fm, Yield, q P with the drought intensity decreases, can according to the logistic equation to fit the data, and WUE, F0,q N does not satisfy the logistic equation; Analysis of Logistic curve shows that the moisture content of the substrate reached 63% maximum water holding capacity, physiological and ecological parameters began to decline, reaching the maximum water holding capacity of about 40%, the rate of decline in physiological and ecological indicators increased; The lower water content of the substrate was 55% maximum water holding capacity, the highest was the highest, and the maximum water holding capacity was 55%~63%.(3)Research on irrigation control system of the elevated cultivation of strawberryAccording to the experimental results above, a set of monitoring and control system for the cultivation of strawberry in greenhouse was developed based on the Internet of things. Firstly, based on the Internet of things, the temperature and humidity sensors and irrigation control equipment suitable for greenhouse cultivation are selected, and a set of Android based irrigation monitoring and control software is designed. At last, a preliminary experiment was carried out on the elevated cultivation test bed in the greenhouse,Experiments show that the system runs stably, when the water content of the substrate reaches the irrigation line, the system can alarm in time, and can realize the automatic irrigation of the system.