LIGHT QUALITY DISTRIBUTIONS AND SPECTRAL ALBEDO OF 3 MAIZE CANOPIES

Spectral attenuation patterns of eight narrow wavebands in the region of 0.4-1.1 μm were measured in three maize (Zea mays L.) canopies. Extinction coefficients were different for visible radiation (PAR) and near-infrared radiation (NIR), but varied little within these spectral regions. Approximately 95% of the visible radiation was intercepted by the canopy and of the available near-infrared 75-80% was intercepted by the canopy. Attenuation patterns and extinction coefficients were different for each of the canopies due to differences in leaf angle and vertical foliage distributions. Visible radiation penetration and albedo were more influenced by canopy morphology than was near-infrared radiation. A single mean value would adequately represent the albedos for each region. Albedo differences within the two spectral regions for the three canopies are attributed to the morphological characteristics of the canopies. © 1979.