Red-edge characteristics of winter wheat canopy spectra

Winter wheat canopy spectral reflectance was field measured using spectrometer Field Spec at different nitrogen levels and time periods. Some red-edge parameters including wavelength (λred), amplitude (dλred) and red-edge apex area (∑dλ680～760)were analyzed for winter wheat leaf chlorophyll (CHL.T), leaf nitrogen content(N%), leaf area index(LAI), accumulated leaf nitrogen content(TN.D), etc. It is found that red-edge positions move to long wavebands till booting stage and then fall back to short bands after booting. A significant correlation is found between dλred and TN.D, CHL.T, and CHL.D. Similar relation exists between ∑dλ680～760 and N%. Red-edge parameters show strong correlation with LAI. It is thus concluded that some red-edge parameters form part of the best remote sensing descriptors.