Fig. 1From: Testing deep placement of an 15N tracer as a method for in situ deep root phenotyping of wheat, barley and ryegrassExperimental sites and methods used in the root phenotyping facility, RadiMax. a The four black squares show units 1, 2, 3 and 4 of the RadiMax facility. The blue squares in units 1, 2 and 3 show the experimental sites with 30 crop rows and the timelines of the four experiments. b The tracer pipes and minirhizotrons were set along the V-shaped bottom in each unitBack to article page