Microtomographic Quantification of Intra-aggregate Pore Geometry

X-ray computed microtomography (CMT) imaging of individual soil aggregates isa relatively recent non-destructive approach useful for quantifying intra-aggregatepore responses to environmental conditions controlling their formation andfunction. CMT can be used to compare intra-aggregate pore geometries withpermeability, ion flux, carbon sequestration and many additional soil water flowproperties controlling biogeochemistries within soil aggregates. Analysis of 3Dporosity, pore size distribution histograms and pore connectivities within soilaggregates from agroecosystem soils will be compared to water retention andhydraulic conductivity measurements. Repeated imaging of the same aggregatefollowing various treatments have been produced by the Advanced Photon Source,ANL and desktop high resolution x-ray CMT scanners. Intra-aggregatemorphological changes, identified by commercial and newly constructedalgorithms, will be discussed. CMT images of pore geometries will be compared tothe organizational configurations of aggregates and their functional contributions tosoil hydrology and carbon sequestration potentials in response to different land useand agronomic practices.