Spectroscopic Approach Toward Unraveling the Electrical Signature of Roots

Abstract

AbstractGeoelectrical methods are increasingly used to investigate soil‐plant interactions in an agricultural context. For this, it is essential to quantify root electrical properties, since they influence the bulk electrical signal of vegetated soil. This quantification has to be done at the root segment scale with attention for the variability of root properties in time and space as well as within and across plant species. In this study, we investigated the frequency‐dependent electrical properties in terms of conduction and polarization of single root segments of Brachypodium (Brachypodium distachyon L.) and Maize (Zea mays L.). A sample holder to investigate the electrical properties of root segments was designed and tested on ideal resistors. We found that it is suitable to assess the electrical properties of crop root segments of 1–5‐cm length in a frequency range between 1 Hz and 45 kHz. The system was then used to obtain the complex electrical response of Brachypodium and Maize root segments at 10 different ages. It was found that the electrical properties of the root segments varied with age and species. This variation was linked to root anatomy based on the microscopic analysis of root sections.