Plant root systems induce biogeochemical patterns in the soil by respiration, water uptake and root exudation that can be measured with in-situ imaging techniques. Slab-shaped rhizoboxes represent the optimum design for 2D optical fluorescence imaging of pH and oxygen dynamics in the rhizosphere as well as measurement of soil water content by neutron radiography. However, quality of standard tomographic (3D) imaging of laterally extended samples suffers from insufficient neutron transmission over a significant angular range. We therefore apply neutron computed laminography (NCL), an adapted tomographic technique especially suited for laterally extended samples, for the first time on plant root systems (Zea Mays) grown in flat, rectangular rhizoboxes (dimensions: 150mm150mm15mm). We successfully obtained the exact position of the roots within the rhizoboxes and could reconstruct and segment the full 3D architecture of the plant root systems. Co-registration of NCL with radiographs and fluorescence images provides a comprehensive insight into root oxygen uptake and rhizosphere pH dynamics of maize. The data is provided as two ZIP archives with TIFF images representing the raw data obtained by 3D neutron computed laminography at the instrument CONRAD-2 as well as the reconstructed dataset of one maize sample.