Root-soil interaction

MRIxXRCT - MRI and X-ray CT based investigation of root-soil interaction of two urban tree species in different soil substrates

Motivation and objectives

Vegetated soils play an important role in enhancing slope stability. Plant root systems contribute to soil reinforcement through both mechanical and hydrological processes. Mechanically, roots increase the shear strength of the soil by binding soil particles, providing additional cohesion, and anchoring shallow soil layers to more stable substrates. Hydrologically, vegetation influences the soil water regime through rainfall interception and root water uptake, thereby reducing soil moisture and pore-water pressures. In addition, roots can modify the hydraulic properties of the soil, affecting water retention and permeability. These combined effects improve slope stability and reduce the risk of shallow landslides. 

However, the spatial and temporal development of root systems and their interaction with the surrounding multiphase soil system under changing moisture conditions remain insufficiently understood.

The aim of the MRIxXRCT project is to investigate the development of root systems of young Robinia and Poplar trees in urban soils under changing moisture conditions. Controlled growth experiments will be conducted using different soil substrates and drought scenarios representative of dry urban summer periods. By combining non-invasive MRI monitoring with X-ray CT imaging, the project aims to characterize root growth and architecture as well as the spatial distribution of soil, water, and air phases. Particular attention will be given to understanding root behaviour and root–soil interactions in the evolving multiphase soil system during drought stress.

 

Project partners

• Institute of Bio- and Geosciences (IBG), Forschungszentrum Jülich

• Institute of Applied Mechanics (IAM), Technische Universität Braunschweig

• Institute of Plant Biology, Technische Universität Braunschweig

Figures, Animations and Poster

Poster presenting X-ray CT-based investigations of root system architecture in Robinia pseudoacacia, with a focus on segmentation uncertainty under different soil moisture conditions. Presented at RootS25 – the 3rd International Workshop on Soil–Vegetation–Atmosphere Interaction, Bari, Italy, 6–8 November 2025.

Contacts
Room 128, Beethovenstraße 51b, 38106 Braunschweig

Univ.-Prof. habil. Dr.-Ing. Marius Milatz
Ilnaz Sarhangi Fard, M.Sc.
Dr.-Ing. Max Wiebicke