Fig. 1

a, b Schematic figures of the RADIX platform with the imaging station moving on rails along a rack holding the rhizoslides. After positioning the station, the rhizoslides can be slid onto the station. Two drip irrigation lines are mounted at the backside of the rack enabling the supply of two different nutrient concentrations. c The imaging station holds two webcams to image the shoot from the side and from the top; a DSLR camera is mounted at 1 m distance from the slide surface to monitor the roots. Roots are illuminated by LED bars (three on each side); illumination is controlled by a microcontroller built and programmed in Arduino 1.0. Rhizoslides on the slide mount can be turned by 180° to image both sides of the rhizoslide. d The dosatron pump system consists of one dosatron supplying base nutrient solution that is split up to two dosatrons allowing for differential nutrient supply. e Scheme of a rhizoslide and the irrigation for the split root setup. High and low N concentrations were dripped into reservoirs from where tubes transported the nutrient solution to the split-nutrient germination paper separated by the wax barrier