Imaging soil structure to measure soil functions and soil health with X-ray computed micro-tomography

Description

The use of non-invasive imaging techniques expands opportunities to characterize soil health and functioning, complementing the information from the traditional soil structure analyses. Soil pore architecture drives water and gas fluxes, chemical transport, activity and movement of soil biota; and imaging techniques are particularly suitable for quantifying it. Here we discuss the potential for X-ray computed micro-tomography (X-ray µCT) as a tool to characterize key parameters of soil pore architecture, such as measures of macroporosity, pore connectivity, pore shape, and solid-to-pore distance. We also provide a brief overview of the principles behind X-ray µCT, examples of the latest literature that implemented these pore measures for soil characterization, and recommendations for the methods that can be used to determine these characteristics using publicly available software ImagJ. We also assembled a list of resources where in-depth information and comprehensive reviews of the current literature can be found.

Table of contents

1 Introduction 2 X-ray computed micro-tomography scanning 3 Soil health-related structure characteristics that can be obtained via X-ray computed micro-tomography 4 Image analysis software 5 Image processing 6 Thresholding 7 Potential indicators of soil health that can be derived from X-ray computed micro-tomography 8 Where to look for further information 9 References