Difference of canopy-air temperature of winter wheat and its affecting factors

In the growth stage of winter wheat, the canopy temperature, air temperature, soil temperature, volumetric soil water content and leave area index were measured for three different water treatments, and canopy-air temperature difference and relationship among canopy-air temperature difference and volumetric soil water content, leave area index were analyzed. The results indicated that influence of different irrigation treatments on canopy-air temperature difference is different; the canopy-air temperature difference on the height of H2 (above canopy) at 14:00 can reflect crop water stress, can be used to examine accuracy of canopy-air temperature by using Remote Sensing methods; change of volumetric soil water content at the depth 60～80 cm can preferably reflect changes of canopy-air temperature difference at 14:00, the coefficient determination respectively are 0.65809(limited water irrigation), 0.99577 (full irrigation), 0.78206(no irrigation); There is also certain relation between leave area index and canopy-air temperature difference of different water treatments, the coefficient determination respectively are 0.76082 (limited water irrigation), 0.40548 (full irrigation), 0.99001(no irrigation).The results of this study can probably be used for monitoring crop water stress and estimating crop yield by combining remote sensing and crop simulation model.