Abstract: 【Objective】Drought is an important factor affecting crop yield and water and nutrient status affect the grade and frequency of drought stress. These complex processes are manifested on a macro scale through the canopy temperature（Tc）of crops. In order to explore the applicability of unmanned aerial vehicle （UAV）infrared thermal imaging technology for monitoring Tc during the formation of complex canopy of densely planted cotton，in this project，a UAV platform equipped with a thermal infrared remote（TIR）sensor is used to study the changes of cotton Tc under different water and nitrogen environments.【Methods】We set irrigation quota（3 150，4 050 and 4 950 m³/hm²）and nitrogen application rate（0，300 and 600 kg/hm²）in Aksu cotton district，Xinjiang，China，The effects of main moisture control measures on the temporal and spatial distribution of cotton Tc were analyzed by converting radiation brightness temperature into actual temperature measurement，the difference of Tc in different treatments cotton，and the change of Tc in different growth periods by the same treatment.【Results】Different irrigation rates and nitrogen application rates could affect cotton Tc. In all 9 treatments，the highest Tc difference reached 6.2 ℃ and the lowest Tc difference reached 1.9 ℃. From 3 150 m³/hm² to 4 050 m³/hm²，Tc decreased significantly. From 4 050 m³/hm² to 4 950 m³/hm²，under normal irrigation conditions，Tc under the 0 kg /hm² nitrogen treatment was 1.8 ℃ higher than that under the 300 kg /hm² nitrogen treatment，and 2 ℃ higher than that under the 600 kg /hm² nitrogen treatment. Under the condition of 4 950 m³/hm² irrigention treatment，the Tc of the 0 kg /hm² nitrogentreatment was 1.5 ℃ higher than that of the 300 kg /hm² nitrogen treatment，and 1.7 ℃ higher than that of the 600 kg /hm² nitrogen treatment. Under the condition of normal irrigation，the Tc of the 0 kg /hm² nitrogen treatment was 1.8 ℃ higher than that of the 300 kg /hm² nitrogen treatment，and 2 ℃ higher than that of the 600 kg /hm² nitrogen treatment. Under the condition of 4 950 m³/hm² irrigention treatment，the Tc of the 0 kg /hm² nitrogen treatment was 1.5 °C higher than that of the 300 kg /hm² nitrogen treatment and 1.7 °C higher than that of the 600 kg /hm² nitrogen treatment.【Conclusion】Tc is significantly affected by irrigation amount. Increasing irrigation amount can effectively reduce Tc，but increasing irrigation amount after reaching a certain degree will lead to Tc increase. Nitrogen application rate can slightly affect Tc，and within a certain range，the higher the nitrogen application rate，the lower the Tc. The use of drones to monitor cotton Tc under different water and nitrogen conditions shows a good difference between treatments，which can be used as a rapid and non-destructive diagnostic technique to evaluate cotton water and fertilizer nutrition to guide cotton precision irrigation and fertilization.

Key words: UAV，infrared thermal imaging，canopy temperature，water and nitrogen status，cotton

摘要： 【目的】干旱是影响作物产量的重要因素，而水分和养分状况影响着干旱胁迫等级和发生频率，这些复杂的过程通过作物冠层表面温度（Canopy temperature，Tc）在宏观尺度上表现出来。为探索无人机（Unmanned aerial vehicle，UAV）红外热成像技术在密植棉花复杂冠层形成过程中监测Tc的适用性，通过UAV平台搭载红外热像传感器（Thermal infrared remote，TIR），研究不同水氮环境下棉花Tc变化规律。【方法】在新疆阿克苏棉区，设置了灌溉定额（3 150、4 050和4 950 m³/hm²）和施氮量（0、300、600 kg/hm²）处理，将辐射亮温转换为实际测量温度，分析主要水分调控措施对棉花Tc时空分布的影响、不同处理棉花Tc的差异及相同处理在不同生育时期Tc的变化。【结果】不同灌溉量和施氮量处理均可影响棉花Tc，在全部9个处理中Tc差值最高达6.2 ℃，最低为1.9 ℃，从3 150 m³/hm²灌量到4 050 m³/hm²灌量，Tc下降明显，从4 050 m³/hm²灌量到4 950 m³/hm²灌量，正常灌溉量条件下，花期施氮量为0 kg/hm²处理Tc较施氮量为300 kg/hm²处理高1.8 ℃，较施氮量为600 kg/hm²处理高2 ℃。花期到铃期时4 950 m³/hm²灌量处理条件下，施氮量为0 kg/hm²处理Tc较施氮量为300 kg/hm²处理高1.5 ℃，较施氮量为600 kg/hm²处理高1.7 ℃。正常灌溉量条件下，花期施氮量为0 kg/hm²处理Tc较施氮量为300 kg/hm²处理高1.8 ℃，较施氮量为600 kg/hm²处理高2 ℃。铃期时4 950 m³/hm²灌量处理条件下，施氮量为0 kg/hm²处理Tc较施氮量为300 kg/hm²处理高1.5 ℃，较施氮量为600 kg/hm²处理高1.7 ℃。【结论】Tc受灌溉量影响显著，增加灌溉量可以有效降低Tc，但是到达一定程度后继续增大灌溉量反而会导致Tc升高，施氮量可以轻微影响Tc，在一定范围内，施氮量越高，Tc越低。利用无人机监测不同水氮状况下的棉花Tc，可较好体现出处理间差异，此技术可作为评价棉花水肥营养的快速无损诊断技术，指导棉花精准灌溉施肥。

关键词: 无人机, 红外热成像, 冠层温度, 水氮状况, 棉花