应用基于红外热画像技术的CWSI简化算法判断作物水分状态

Application of a Simplified Method for Estimating CWSI with Infrared Thermography

以不同水分处理下的冬小麦为研究对象,通过基于红外测温技术的Jackson理论模式和Jones简化模式分别计算作物水分胁迫指数(CWSI),并以理论模式计算值为参考,对Jones模式反映华北地区冬小麦水分胁迫的表现进行初步分析。结果表明,两种计算模式得出的CWSI值与不同水分处理下的冬小麦根层土壤含水量均有较好的相关性,但Jones模式可更好地指示作物缺水状态,对叶片气孔导度的变化更敏感。根据研究结果初步确定了冬小麦高产条件下的CWSI阈值。本研究显示Jones简化模型能准确反映作物水分状态,并易于实现田间多点观测,可用于准确指导农田灌溉。

Taking winter wheat （ Triticum aestivum L. ） as material, crop water stress index （CWSI） was calculated by using two methods： Jackson＇s theoretical model and Jones＇ simplified model with the technology of the visible and thermal infrared imagery under different irrigation schedules. The validity and feasibility of Jones＇ method for monitoring winter wheat water stress in the North China Plain （NCP） was briefly analyzed refer to theoretical CWSI. The results showed that CWSI calculated by the two models had closed relationships with the soil moisture conditions of the main root-zone soil profile under 6 irrigation schedules. Moreover, Jones＇ method was more sensitive to the subtle changes of crop water status and had a better response to the changes in stomatal conductance of winter wheat Threshold values of CWSI were determined initially for maximizing the yield of winter wheat based on two different models. The results indicated that Jones＇ simplified model was a practical and reliable method for monitoring crop water status, which could be used to establish a readily portable system for spot measurements in crops and guide irrigation scheduling accurately.