Supplementary material to "How do roots interact with layered soils?"

Supplementary material to "Kemp, N., Angelidakis, V., Luli, S., Nadimi, S. (2021). How do roots interact with layered soils?" This document reports geotechnical data from image processing of 30 images, emerging from CT scans of 2 soil-root samples A and B, for 5 stages of root growth corresponding to 1,4,8,11 and 15 days after germination and for 3 machine learning-based classifiers used for image segmentation, trained using 5%, 10% and 20% of the total number of images. Both samples feature layered soil, made of clay, silt, sand and gravel (Sample A: gravelly top layer - Sample B: clayey top layer). Values of void ratio and root volume ratio versus elevation are provided, considering regions of interest of various sizes.