Light interactions, use and efficiency in row crop canopies under optimal growth conditions

摘要: Abstract Accurate estimates of light (Photosynthetically Active Radiation or PAR) absorption, in addition to other interactions is imperative quantify growth, productivity, energy and water balance physiological biophysical processes any vegetative surface. Currently, a comparative assessment interaction patterns across row crops lacking, especially under current levels productivity achieved the U.S. High Plains. Here, we continuously measured canopy components at high-frequency (15 min) characterize transmittance (R), reflectance fraction intercepted PAR (fIPAR), absorbed (fAPAR), extinction coefficients (k), use efficiency (LUE) comparatively maize, soybean, sorghum winter wheat optimal growth conditions. While maximum fAPAR was 88-96% incoming all crops, mean varied from 82% 46% wheat; while k ranged 0.36 (winter wheat) 0.48 (sorghum soybean), these differences reflect highly crop-specific signatures. Conversion factors among fIPAR LUE based on either component (LUEi LUEa) were quantified that substantially different conventionally used values; during early late stages. A commonly employed approach solar-noon sampling evaluated, it found stages crop experience greater potential errors (as high as 110%) this approach, hence should be avoided. LUEa highest for maize (5.3 g MJ−1), followed by (4.1 (4.0 MJ−1) soybean (3.1 MJ−1). The datasets measured, analyzed interpreted here present unprecedented quantities biomass parameters four major cropping systems, hence, accounted modeling applications enhance predictive accuracy robustness.