Application of X-ray computed tomography to soil science: A literature review

Abstract

T. R. 2008. Application of X-ray computed tomography to soil science: A literature review. Can. J. Soil Sci. 88: 1Á20. The study of the spatial configuration of soil, in its complexity, requires an understanding of the interrelations and interactions between the diverse soil constituents, at various levels of organization. Investigations of the spatial arrangement of the mineral and organic components of soil have benefited from the development of techniques for structural analysis. X-ray computed tomography (CT) is a non-destructive and non-invasive technique that has been successfully used for three-dimensional (3D) examination of soil. Valuable information has been obtained by the application of CT for the description and quantitative measurements of soil structure elements, especially of soil pores and pore network features. In many studies, X-ray CT has been used to investigate the hydro-physical characteristics of the soil, in a functional and temporal manner. A dynamic approach has also been utilized in the evaluation of the biotic factor influence on soil. The analysis of soil solid phases, by X-ray CT, has been challenging due to the similar X-ray attenuation of different solid constituents. However, the use of multiple X-ray energy levels has facilitated the discrimination of minerals in soil. The aim of this review and synthesis is to offer a perspective on the major issues related to application of the technique, general attempted solutions and possible directions in the utilization of X-ray CT in soil research. Relevant scanning parameters, procedures for CT image reconstruction, algorithms for the quantification of soil characteristics and results are presented for each type of application.Key words: X-ray computed tomography, energy level, spatial resolution, segmentation, soil mineral and organic constituents, soil physical and hydro-physical properties, soil biota Taina, I. A., Heck, R. J. et Elliot, T. R. 2008. Application de la tomographie aux rayons X a`la science du sol : survol de la litte´rature. Can. J. Soil Sci. 88: 1Á20. Pour e´tudier la configuration spatiale du sol dans toute sa complexite´, il faut comprendre les relations et les interactions des fractions du sol a`diffe´rents niveaux d'organisation. Les recherches sur l'organisation spatiale des couches mine´rales et organiques du sol ont profite´du de´veloppement de techniques d'analyse structurale. La tomographie aux rayons X assiste´e par ordinateur (TXAO) est une technique non destructive et non invasive qu'on a applique´e avec succe`s a`l'analyse tridimensionnelle du sol. L'usage de la TXAO pour de´crire et quantifier les e´le´ments structuraux du sol, surtout les pores et les particularite´s de leurs re´seaux, a permis de glaner quelques pre´cieuses informations. Maintes e´tudes rapportent qu'on s'est servi de la TXAO pour pre´ciser les proprie´te´s hydrophysiques du sol sur le plan fonctionnel ou temporel. On a aussi recouru a`une approche dynamique pour e´valuer l'influence des facteurs biotiques sur le sol. L'analyse des p...

Three-dimensional distribution of water and air in soil pores: Comparison of two-phase two-relaxation-times lattice-Boltzmann and morphological model outputs with synchrotron X-ray computed tomography data

“…Several soil microbiologists have pointed it out already for more than half a century [1]. However, not much could be done by way of a response until roughly 15 years ago, when significant technological breakthroughs allowed the geometry of the pore space in soils to be visualized, and the spatial heterogeneity of a number of chemical and mineralogical constituents of soils to be quantified at micrometric scales commensurate with fungal hyphae and even the most minute of bacteria or archaea [48,40,9,6,7,8].…”

Application of x-ray computed tomography in the evaluation of soil porosity in soil management systems

“…TAINA et al (2008) argued the perfect discriminations of soil phases by simple thresholding may be difficult in some situations, due to attenuation and partial volume effects, especially when X-ray computed tomography instruments with different performances are employed.…”

“…Nowadays, advanced techniques of image processing allow to quantify the pore volume and to represent the object in three dimensions (PETH et al, 2008;TAINA et al, 2008).…”

La micro-tomographie RX, un outil pour une analyse anatomique fine du bois

“…In addition to aforementioned techniques, X-ray tomography is explored in this paper as a tool for detailed anatomical research. It is a technique used in several research disciplines such as medicine (Fu and Kuduvalli, 2008), soil science (Taina et al, 2008), hydrology (Wildenschild et al, 2002), entomology (Fuchs et al, 2004), plant physiology (Lee and Kim, 2008) and material science to name only a few. Even in wood science, its possibilities are employed.…”