作物冠层表面温度诊断冬小麦水分胁迫的试验研究

利用红外测温装置能够观测获得作物的冠层表面温度,从而诊断作物是否遭受水分胁迫。基于这种技术,使用作物水分胁迫指数CWSI反映我国华北平原地区冬小麦的水分胁迫状况。研究比较了作物水分胁迫指数CWSI的经验模式和理论模式,根据它们的波动特征,可以看出用CWSI经验模式反映华北地区冬小麦水分胁迫不很理想。研究分析了作物水分胁迫指数理论模式与其他一些反映作物水分状况的指标,包括叶水势、叶片气孔阻力,叶片最大净光合速率以及土壤水分含量之间的关系,结果表面理论模式与上述这些指标关系良好,表明其很好地反映了作物的水分胁迫特征。该研究给出了适合于我国华北平原地区冬小麦的作物水分胁迫指数计算的主要参数。研究从实际田间应用的可能性出发,分析并提出了作物水分胁迫指数经验模式和理论模式应用的改进方向

Winter Wheat Water Stress Detection Based on Canopy Surface Temperature

Infrared thermocouple temperature (IRT) sensor can estimate crop canopy surface temperature by measuring infrared radiation, on this basis, crop water stress can be monitored. In this paper, the Crop Water Stress Index (CWSI) was applied, which can be calculated by using the crop canopy surface temperature from IRT sensor, to detect the water stress for winter wheat (Triticum aestivum L.) in North China Plain (NCP). The theoretical and empirical models of CWSI were compared in this paper. The results indicate that the empirical model is not the better tool to detect winter wheat water stress in NCP due to its large fluctuation. The relationship between theoretical CWSI and the other parameters of the crop water stress, including soil moisture, leaf water potential, leaf stomata resistances and leaf net photosynthesis, was analyzed. The close correlation between them shows that the theoretical CWSI is a good indicator to detect winter wheat water stress in NCP. This paper gives the main parameters for calculating CWSI for winter wheat in NCP. Considering the feasibility of applying CWSI, the two ways to improve CWSI for monitoring winter wheat water stress and irrigation scheduling were suggested.