Research On Water Press Monitor And Irrigation System On The Basis Of Virtual Instrument For Poplar Seedlings

With the development of computer and softwares technic, the virtual instrument is becoming thedevelopment direction in the tests realm gradually, adopting the virtual instrument to carry out AEsignal monitor and analysis is becoming the development trend of the modern test realm.Therefore, this topic study with PC as the hardware and take the LabView of the Americannational instrument(NI) company as the software, match with the necessary sensor, signaladjustment and data collect card which of them constitute the system of water stress acousticemission monitoring and the irrigation control. This system is made up of the temperature sensor,humidity sensor of the soil and acoustic emission sensor which of them turn temperature of atmosphere,the amount of water in the soil and the acoustic emission signal of plant due to the water stress into theelectric voltage, then use the virtual instrument to collect electric voltage signal of inputting the datacollect card. Saved the data as the type of data log file, carry out statistical analysis at the same time,show the data synchronously and export the switch signals, control the electromotor through a datacollect and control card, in order to control of the water dripping with the electromagnetism valve,regulate the humidity of the soil, lower the frequency of acoustic emission signal, still show thefeedback signal on the operate platform at the same time.The paper introduce monitor theories of the water lacking firstly, analysed the method of monitorand the development deeply; then elaborate the total project design of monitor system in the virtualinstrument. This system is circulate in the environment of Windows XP, the whole system includes thedata collect, the signal adjust, handle, saving, automatic control and manifestation. Each part of themadopts the modular program.The irrigation experiment researches the relation of acoustic emission signal and plantphysiological water of demand, factors of environment, based on the research object of poplar nurserystock. The experiment result expresses: Poplar nursery stocks are controlled to irrigate by acousticemission signal that is produced by water stress, which does not differ much from other irrigatecontrol. Moreover, it is a good automatic control index for irrigation, and is sensitive to waterdeficit. For that reason, the paper expands the system function based on monitor system, builds up adrop irrigation automatic control system depending on physiological demand water message of poplarnursery stock, and carries on the irrigation control experiment. Meanwhile, because of adopting a high standard water kind of irrigation method as well as alternating wet and dry irrigation method with rootzone dividing, which ditches in two side of nursery stock and distributes aligning in two side of tap, itcan not only save water 31% and 39% respectively, but also not harm plant growth, according toacoustic emission control irrigation, and saving-water effect and economic benefit are remarkable,compared with timing irrigation and whole wet irrigation. The experiment in north test field of Bao-dingcity proves that the system has a lot of advantages, for instance, steadily and reliably to work, easy andflexibly to operate, accurate to test result, and it adapts the demand of modern agriculture and forestryproduction and automated management, and it provide a new research method for the plantphysiology, ecosystem and water saving irrigation, it has a higher practical(use) value and the broadapplication.