3-Dimensional characterization of substrates with X-ray microtomography

P.C. Bartley, B.E. Jackson, W.C. Fonteno
X-ray tomography is an imaging technique pioneered by the medical and petroleum industries to spatially characterize materials. Advances in X-ray technology, software, and commercially available instruments have opened the door for its utilization in horticultural substrate research. Tomographic reconstruction of rooting matrix could provide 3-D, in situ characterization of substrate particles, pore structure, and root architecture. An X-ray microtomography instrument was used to scan pine bark, sphagnum peat, coconut coir, and wood fiber substrates. Each material was scanned at a resolution of 50, 35, and 25 μm and evaluated qualitatively. At all resolutions, materials were effectively scanned with clear distinctions between pores, substrate particles, and roots. Increasing the scan resolution resulted in more definable internal pore structures observed most notably in pine bark. Three dimensional surfaces were successfully rendered at each resolution and for each material. These results demonstrate that horticultural substrates could be visualized during root development, opening new opportunities for the application of X-ray microtomography in experimental studies concerning substrate characteristics and plant interactions.
Bartley, P.C., Jackson, B.E. and Fonteno, W.C. (2019). 3-Dimensional characterization of substrates with X-ray microtomography. Acta Hortic. 1266, 1-6
DOI: 10.17660/ActaHortic.2019.1266.1
image analysis, particle size, particle shape, rootball matrix, soilless substrate

Acta Horticulturae