The Research Of The Decision Support System Of Greenhouse Crops Irrigation

This paper pointed out many disadvantages of our now experience-based irrigation. The author deeply studied the decision support system of irrigation of the cucumber and romaine lettuce based on the transpiration rate and greenhouse environment factors —temperature, humidity and light. Main results as follows:(1) Based on the field experiment, the author analysed the varying character of crop transpiration rate with different temperature, humidity and light, and established the crop transpiration rate diagnose model on the basis of the varying regular of the crop transpiration rate with different soil moisture handle. According to the transpiration rate diagnose model, in sunny day and cloudy day in every season, the author divided the transpiration rate into three regions, region with abundant water indicates that soil water is more than 90% of field capacity, region with suitable water indicates that soil water is between 60% and 80% of field capacity, and region with water deficit indicates that soil water is less than 50% of field capacity.(2) With collecting the environment factors inside of the greenhouse during given cultivation stage and calculating the irrigation amount of the crop, the author established the relational function between the temperature, humidity, light and the irrigation amount with the method of regress analysis.(3) Based on the testing data, the author established the model base, database and rules during decision. The system is programmed by Visual basic 6.0. It has a friendly interface. For example, the system can give the theory value of irrigation when crop name, sensor name, temperature, humidity and light are inputted.This paper will develop a new researching domain for greenhouse crops irrigation. And the fruit of this study will provide scientific basis for development of measurement of crop physiological thirst information and control system of water-saving irrigation.