Synchrotron-based techniques for plant and soil science: opportunities, challenges and future perspectives

Spectroscopic approaches to plant and soil sciences have provided important information for several decades. However, many of these approaches suffered from a number of limitations and drawbacks especially in terms of spatial resolution and requirements for sample preparation. The advent of dedicated synchrotron facilities, that allow the exploitation of the particular qualities of synchrotron radiation as a research tool, has revolutionised the way we approach the investigation of nutrients and contaminants in environmental samples. Various synchrotron-based techniques are currently available that permit such investigations in situ and at the molecular level. The continuous development of these techniques is delivering substantial gains in terms of sensitivity and spatial resolution which allows analyses of diluted samples at the sub-micron scale. This paper aims at providing an introduction to synchrotron radiation and to the fundamentals of some widely used synchrotron-based techniques, in particular X-ray absorption, fluorescence and tomography. Furthermore, examples are provided regarding the applications of synchrotron-based techniques in the field of plant, soil and rhizosphere research. Finally, current limitations and future perspectives of synchrotron techniques are discussed.