Analyses of spectral-biophysical relationships for a corn canopy

The empirical study reported in this article focused on the relationships between vegetation properties and reflectance measured on a corn canopy throughout its phenological evolution by means of a truck-mounted speetroradiometer. The objective was to produce relationships between spectral indices [such as normalized difference vegetation index (NDVI) and the wavelength of the red edge] and biophysical parameters, such as leaf area index (LAI) and biomass, which should be useful for corn studies from remotely sensed data. The NDVI and the red-edge position were both found useful to describe some phenological stages for a corn canopy, because they both correlated statistically significantly with biophysical parameters, such as LAI and biomass. Coefficients of determination (r2) for the various relationships ranged from 0.94 to 0.98: however, leaf area index could be best estimated from NDVI by exponential equations, and biomass from the wavelength of the red edge by logarithmic equations.