棉花冠层高光谱指数与叶片氮积累量的定量关系

利用冠层高光谱反射率及演变的多种高光谱植被指数(VI)，分析了不同施氮水平下不同棉花品种叶片氮积累量与冠层反射光谱的定量关系，建立了棉花叶片氮积累量的敏感光谱参数及预测方程。结果显示，棉花叶片氮积累量和冠层高光谱反射率均随不同施氮水平显著变化；棉花叶片氮含量的敏感光谱波段为600~700 nm的红谷波段和750~900 nm的近红外波段，叶片氮积累量与光谱指数NVD672有密切的定量关系，且不同品种可以用统一的方程来描述，从而为棉花氮素营养的监测诊断与精确施肥提供了技术支持。

Relationship between Canopy Hyperspectral Index and Leaf Nitrogen Accumulation in Cotton

It is very important to develop nondestructive methods for estimating nitrogen status and growth characters in cotton. Based on the canopy hyperspectral reflectance and derived hyperspectral vegetation index, we analyzed the quantitative relationships between leaf nitrogen accumulation and canopy reflectance spectra in different cotton cultivars under varied nitrogen rates, and put forward the sensitive parameters and monitoring equations for leaf nitrogen accumulation. The results showed that the leaf nitrogen accumulation and canopy hyperspectral reflectance significandy changed with levels of nitrogen fertilization. The sensitive wavebands of leaf nitrogen accumulation were 600-700 mn of red valley and 750-900 mn of near infrared wavebands, and the leaf nitrogen accumulation was siguificantly related to NVD672 of canopy reflectance spectra, and an integrated equation could be used in different cultivars. These results provide technical approach for monitoring plant nitrogen status and guiding precision nitrogen management in cotton production.