In the project we develop methods to nondestructively visualize and quantify plant root system architecture within soil using X-ray CT (Koebernick et al. doi:10.2136/vzj2014.03.0024) . Repeated scanning of individual root system enables us to capture the dynamics of root growth and its response to soil drying. Furthermore, the evolution of root-soil contact and the development of an air gap between roots and soil as a consequence of plant water stress are investigated. The reconstructed root systems are used in the detailed three-dimensional root water uptake model R-SWMS (Javaux et al., 2008) to analyze the impact of root system architecture on root water uptake.