Sensing of photosynthetic activity of crops

Abstract

The light use efficiencylight use efficiency of photosynthesisphotosynthesis dynamically adapts to environmental factors and is one major factor determining crop yield. Optical remote sensingremote sensing techniques have the potential to detect physiological and biochemical changes in plant ecosystems, and non-invasive detection of changes in photosynthetic energy conversion may be of great potential for managing agricultural production in a future bio-based economy. Here we give an overview on the principles of optical remote sensingremote sensing in crop systems with a special emphasis on investigating hyperspectralhyperspectral reflectance data and the sun-induced fluorescencefluorescence sun-induced fluorescence signal. Especially sun-induced fluorescencefluorescence sun-induced fluorescence as a parameter, which becomes important in remote sensing research may have great potential quantifying the physiological status of the photosynthetic apparatus. Both remote sensing principles were applied during the CEFLES2 campaign in Southern France, where the structural and functional status of several crops was measured on the ground and using state-of-the-art optical remote sensing techniques. Sun-induced fluorescence chlorophyll fluorescence measurements over a variety of crops showed that additional information can be retrieved also over dense canopies, where classical remote sensing signals often saturate. With a view to the future, we discuss how hyperspectralhyperspectral reflectance and sun-induced fluorescencefluorescence sun-induced fluorescence can quantitatively be related to photosynthetic efficiency and help to measure and manage productivity of natural and agricultural ecosystems.