Healthy soils for sustainable agriculture: the role of SOM
3–7 September 2017 • Rothamsted Research • Harpenden (United Kingdom)
Chair: Wilfred Otten (Cranfield University, UK)
This session invites presentations that demonstrate advances, applications and challenges in imaging soil organic matter at the pore scale. Micro-environmental conditions are key for protection of soil C. However, quantitative knowledge of the mechanisms driving micro-environmental effects is still limited, as processes operate at these scales are well below the scale at which the majority of studies were able to observe. Over recent years due to the advancement of various techniques it is now possible to circumvent these problems and investigate the fine structures of C as well as directly image organic C forms at nano- and micro-meter scale. Such techniques include the use of non-invasive synchrotron based Scanning Transmission X-Ray Microscopy (STXM) and Near Edge X-ray Absorption Fine Structure microscopy (NEXAFS) but more recently also readily accessible benchtop X-ray CT in combination with various staining applications, or through merging of multiple techniques applied to 2D and 3 D soil volumes. To date these advances have already delivered valuable novel insights into compositional chemistry and linkages between C and the mineral matrix. Other examples include the visualisation of particulate organic matter within aggregates, degradation of roots, or the movement of root exudates through the rhizosphere with PET scanning. Recent studies using these exciting emerging techniques that visualise soil organic matter at micro-scales scales are presented in this session together with current challenges in going forward.