Table I. X-ray μCT scanner settings and image data properties.

Experimental set up: plant species, soil textural type, and x-ray μCT scanner settings. Plants were grown in an environmentally controlled growth room with 16-/8-h light cycle (*, greenhouse). All plants were imaged in soil with water content approximately at field capacity.

Plant Species	Wheat	Wheat	Wheat	Maize*	Tomato	Tomato
Soil textural type	Sand	Sand	Sand	Loamy sand	Clay loam	Loamy sand
Voltage	130 kV	130 kV	130 kV	80 kV	110 kV	110 kV
Current	90 μA	90 μA	110 μA	160 μA	180 μA	180 μA
Filter	1 mm aluminum	1 mm aluminum	1 mm aluminum	None	0.1 mm copper	0.1 mm copper
No. of projections	1,440	1,440	1,440	1,200	1,200	1,200
Resolution (per voxel)	28.75 μm	28.75 μm	28.75 μm	44.23 μm	23.91 μm	23.91 μm
Detector exposure time	1,000 ms	1,000 ms	1,000 ms	250 ms	1,000 ms	1,000 ms
Binning mode	1 × 1	1 × 1	1 × 1	2 × 2	1 × 1	1 × 1
Signal averaging	4 (1 skip)	4 (1 skip)	4 (1 skip)	6 (3 skip)	1 (0 skip)	1 (0 skip)
Images in stack after reconstruction	1,800	1,800	2,000	771	1,313	1,698
Image dimension after reconstruction (pixels)	864 × 864	864 × 864	876 × 872	678 × 668	1,388 × 1,404	1,404 × 1,380