Research And Development Of The Intelligent Diagnosis System For Water Status Of Greenhouse Crop

Modern greenhouse agriculture has been widely applied throughout the world,since it has broken through the traditional agriculture limitation which is influencedby factors such as region, climate as well as season, so as to provide suitable andfavorable environmental conditions for crop growth. The practical experiencesconcluded by developed countries like Israel and American indicate thatinformatization and intelligentization of greenhouse irrigation management hassignificant influence on saving energy and water, liberating labour and improvingproduct quality. The accurate diagnosis of crop water status is the importantprecondition for automatic and precise irrigation in greenhouse. The scientificdiagnosis of crop water status and precise control for irrigation in our country startedrelatively late. Irrigation decision relating a lot kind of greenhouse crops were stillmainly rely on experiences, or just rely on measuring soil water content to diagnosecrop water status. Inherent factors in crops were rarely considered. Through queryingand collecting associated theory and latest research conducted by agricultural experts,we have constructed professional knowledge system which best suit irrigatinggreenhouse crops. Meanwhile various kinds of scientific and reliable diagnosismodels which suit greenhouse crops were selected, diagnosis irrigating system whichwas low-costing, easy to exploit, widely applied and also with high stability wasdeveloped. The main research contents and results are described as follows:(1) Considering various factors that influence diagnosis of crop waterdeficit, combining special microclimate environmental characteristics ingreenhouses, this paper has selected four reliable and super suitable models diagnose crop water deficit in greenhouses, including soil water method, canopy leaf-airtemperature method, diagnosis method base on Penman-Monteith equation as well ascrop stem diameter micro-variation method. Among them, diagnosis method base onPenman-Monteith equation was conducted according to water balance principle, usingmoderated Penman-Monteith equation suitable for greenhouses to calculate referencecrop evapotranspiration and soil water content at the end of every day combiningwater balance theory, then diagnose water deficit condition by comparing with soilwater lower limit.(2) Basing on different characters of latent parameters like proper water statuscrop factors with different growth stages and different environmental conditions,using MySQL database management system, we have designed the irrigationmanagement database system of greenhouse crop, as so to offer technique platform ofimproving the accuracy and efficiency of crop water diagnosis in greenhouses.(3) By applying Borland C++Builder(XE2)soft development platform、MySQL(5.1)data base management system, we have researched and developedintelligent diagnosis system of crop water status in greenhouses with high universalityand friendly interface. Users only need to input basic parameters required and selectsuitable diagnostic model, the system can accurately diagnose present water deficitcondition of crops by accessing crop environment information in time. At the sametime, irrigation requirement can also be calculated to offering reliable decision basisof intelligently control irrigation in greenhouses. The system has integrated fourdiagnostic models of crop water and the applicability has been improved, all thesemade it beneficial to put into application. By experimental application of water deficitdiagnose of greenhouse tomato, we have verified the stability of system operation、liability of diagnosis and simplicity of operation.(4) Taking greenhouse crop water deficit diagnosis system as kernel, bydeveloping greenhouse crop information collecting system based on Zigbee wirelesstransmission and irrigating execute terminal, we have established remote controlplatform of greenhouse intelligence irrigation so as to realize intelligent irrigatingeffect to crops that is in time and accurate. Moreover, the sharing of resources wasrealized through utilizing the Internet, which allowed common managers of greenhouses to make use of the platform to conduct remote control management ofgreenhouse crop irrigation.