Evaluating the contribution of complementary radiation on photosynthesis of maize canopy with 3D radiative transfer model

Photosynthesis of a canopy is primarily determined by its interception of solar radiation. Previous studies used to ignore the effects of complementary radiation (radiation scattered by canopy components) by taking leaf as black body in calculating the interception of photosynthetic active radiation. However, some recent researches suggested that complementary radiation may raise light utilization efficiency of plant canopy and its influence on photosynthesis cannot be ignored. In this study, Parallel Monte Carlo ray tracing model for three-dimensional canopy was employed to simulate the process of radiative transfer within maize canopies for quantifying the complementary radiation from leaves and its contribution to canopy photosynthetic production. It is suggested that scattering radiation can play a significant role in the middle and lower layers of a dense maize canopy and its contribution to light interception and photosynthetic production in a canopy is dependent on the solar elevation and canopy structure parameters such as leaf area index and leaf area density.