Current deficiencies and needed enhancements on greenhouse crop evapotranspiration models
Determination of greenhouse evapotranspiration(ETc)is important in making the accurate irrigation schedule,improving the agricultural water using efficiency,and increasing the yield and quality of the greenhouse vegetables.The advantage,disadvantages and applicability of the direct and indirect ETc models,different reference evapotranspiration(ET0)models for greenhouse crops were analyzed,and the accuracy of the direct mechanism ETc models was compared,the models for determi-nation the key parameters(canopy resistance parameters)and its influence factors were summarized and analyzed.The previous studies have mainly corrected the canopy resistance parameters and verified the accuracy of the model for specific climatic regions,greenhouse ventilation types,crop types and planting seasons.The universality of the greenhouse crop ETc model is not sufficient,and the deter-mined model parameters are often not applicable to other types of greenhouse or crop planting seasons.However,the applicability of these ETc models and parameters in different type of ventilated greenhou-ses and crop needs to be validated.Hence,it is recommended to focus on the following research on the response characteristics of the greenhouse ETc to the climatic variations,the comprehensive analysis of the applicability of the different mechanism ETc models to the climatic and crop types,and the con-struction of the much applicability and high accuracy ETc models.
evapotranspiration modelsgreenhouse typeventilationmeteorological datacrop type