In modern agriculture drought is a major cause of low yields worldwide. Therefore, imaging systems that enable to study the interactions between plant and soil are a way towards better understanding of crop water supply. The main objective of root measurement is to obtain new knowledge on key functioning of roots. An important aspect is that the roots should be measured in their natural soil environment to obtain information not only on root architecture but also on root functioning. Within this research project a VIS imaging setup and a NIR hyperspectral imaging system for the acquisition of hyper-spectral NIR image data of rhizoboxes were developed. The combination of imaging using the VIS wavelength range (380nm to 780nm) and imaging spectroscopy using the NIR wavelength range (900nm to 1700nm) provides several advantages. The VIS imaging setup is used to provide quick overview images at different development states of plant roots. The hyperspectral NIR system provides increased image contrast which allows for a more reliable segmentation of the roots from the soil and additional information, e.g. basic root-architecture, to be extracted. Moreover, it is possible to visualize the water distribution in the soil in close proximity to the roots. In this paper the hardware setup of the NIR imaging spectroscopy system, the data analysis, the soil water distribution measurements and the root segmentation are presented.
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