Remote estimation of fraction of radiation absorbed by photosynthetically active vegetation: generic algorithm for maize and soybean

The objective of this study is to develop generic algorithm for estimating fraction of radiation absorbed by photosynthetically active vegetation not requiring parameterization for C3 and C4 crops, maize and soybean, with contrasting photosynthetic pathways, canopy architectures and leaf structures. The study based on data acquired during eight years, altogether 16 site years of maize (12 irrigated and 4 rainfed, nine hybrids) and for 8 site years of soybean (4 irrigated and 4 rainfed, three cultivars). The red edge normalized difference vegetation index (NDVI), green NDVI and wide dynamic range vegetation index (WDRVI) were found to be accurate in estimating fraction of photosynthetically active radiation (PAR) absorbed by photosynthetically active green vegetation in maize and soybean with root mean squared error (RMSE) of 0.057, 0.067 and 0.069, respectively.