Research On Soilless Cultivation System Of Vegetables By Imitating Rotation

In order to solve the problem of low utilization efficiency of nutrient solution for vegetable soilless cultivation and high nitrate content of leafy vegetables,combined with the previous research on aeroponics of vegetables,based on the traditional agricultural essence-rotation cultivation,Soilless cultivation mode by imitating rotation is put forward.And a small soilless cultivation device suitable for the cultivation mode is designed and processed.And an automatic control system for nutrient solution with disinfecting function was developed.So,a better soilless cultivation mode by imitating rotation is selected.Finally,a soilless cultivation system by imitating rotation was established.Main research contents:A set of imitating rotation soilless cultivation device was developed by coupling aeroponics and rockwool soilless cultivation technique,with dimensional cultivation mode.And an aeroponics container,rockwool,ozone generator conveying ozone to the nutrient solution buffer container for nutrient solution disinfection and a nutrient pool equipped with a UV lamp are contained in the device.And other equipments are selected.And nutrient solution circulation mode was used,with coupling ozone antivirus and UV antivirus.What's more,this device which utilized in the existed small plant factory can also be applied independently in other environments,provides equipment assurance for the realization of imitating-rotation soilless cultivation.An automatic monitoring system of nutrient solution for soilless cultivation of vegetables,which realize the real-time detection and automatic regulation of pH and EC value of nutrient solution in soilless cultivation,was designed by developing hardware and software.And pH and EC signal acquisition circuit and driving electromagnetic valve circuit were designed through hardware development,with STC89C52 microcontroller selected as a processor.And signal acquisition module,automatic control module and display module were contained in the software,so that the whole system was simple and run smoothly.The system is tested stably: The maximum error for pH measurement is 0.16,50 min on the acidic,neutral and alkaline solution for continuous measurement of the data variance were less than 0.003,EC measurement maximum error of 5?s/cm,50 min continuous measurement of data variance of 24.Mode(1)—Lactuca sativa L.var.ramosa Hort.of aeroponics and Raphanus sativus L.Var.radculus pers of rockwool soilless cultivation technique and mode(2)—Lactuca sativa L.var.ramosa Hort.of aeroponics and Pisum sativum.Linn of rockwool soilless cultivation technique are established as imitating rotation soilless cultivation mode.Compared with the same culture conditions,the imitating rotation soilless cultivation is better:the nitrate content of lettuce reduced by 14.14% and 28.29%,the nitrogen utilization rate of cultivated system increased by 41.76% and 62.73%,the energy input per unit biomass decreased by 30.71% and 47.19%,at the same energy consumption condition,the total output value of the cultivation system increased by 30.30% and 53.88%.Compared with each other,mode(2)is better than the model(1): nitrogen use efficiency increased by 13%,unit biomass energy reduced by 23.8%,total output increased by 44.45%.