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 significantly changed with levels of nitrogen fertilization.The sensitive wavebands of leaf nitrogen accumulation were 600700 nm of red valley and 750900 nm of near infrared wavebands,and the leaf nitrogen accumulation was significantly 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.