P23 - Physics & Mechanics

Localization and quantification of physical and mechanical rhizosphere properties using X-ray microtomography and micro-sensing techniques


The aim of this project is to non-invasively image and study the evolution of structural patterns in the rhizosphere using soil column experiments (SCE) via X-ray computed tomography and quantitative image analysis. Two textures and genotypes from the central experimental platform will be used to investigate hydraulic and mechanical processes during root growth in a series of experiments. Aim is to use two different moisture contents: an “ideal” and a water-stressed treatment. The water content of this treatment will be determined with a pre-test and should allow sufficient, yet distinctly modified root growth. Our hypothesis is, that the resulting root structure under drought conditions, will be specific to soil texture and maize genotype. Tool-IP will be used for image analysis of pore and root system. Furthermore, deformation patterns will be identified using DaVis, a specialized software based on digital image correlation.
The distribution and transport of oxygen in the rhizosphere has a great impact on microbial activity and bio-chemical reactions and will be analysed by using micro-sensors after the harvest of the plants of the SCE. In collaboration with the working group at the University of Bayreuth the effect of mucilage and soil moisture on micro-mechanical processes during root penetration will be studied. For this workpackage a series of mechanical tests is planned, including penetration resistance, compression and shear vane tests. Another cooperation is planned with the Technical University of Munich regarding rhizodeposition and its effect on structure formation in the rhizosphere by applying novel staining techniques to visualize micro-scale soil organic matter distribution.

Link to English scientific abstract

Link to German scientific abstract