Investigation of Anisotropy in Induced Polarization Signatures of Maize Root-Soil continuum: A Virtual Rhizotron Study

Rao, Sathyanarayan [UCL] Ehosioke, Solomon [Applied Geophysics, Université de Liège, Belgium] Kemna, Andreas [Department of Geophysics, University of Bonn, Germany] Nguyen, Frédéric [Applied Geophysics, Université de Liège, Belgium] Garré, Sarah [TERRA Research and Teaching Center, AgroBioTech Gembloux, Université de Liège, Belgium] Javaux, Mathieu [UCL]

A numerical electrical conductivity model was coupled with a plant-soil water flow model to investigate the impact of plant root architecture and water uptake pattern in a rhizotron on the frequency dependent induced polarization (IP) signature. The roots were explicitly represented with their frequency dependent electrical properties in the finite element mesh, including the properties of cortex and stele. Our experiments on maize root segments indicate that roots are strongly polarizing in terms of frequency dependent complex conductivity spectra and is a function of root properties such as root surface area, root type and root age. The effective electrical conductivity (bulk property) of the soil root medium computed using simulated plate electrodes at boundaries reveal that anisotropy factor induced by root system architecture can be used to identify or quantify root system structural properties. In our model, different Maize root architectures are considered and their effective IP properties are investigated.