The potential of electrical imaging for field root zone phenotyping

Providing enough food for a growing population while preserving natural resources and biodiversity is one of the challenges of the 21st century. A key pathway to maximize yields in a sustainable way is to select and grow crops that are optimally adapted to their environment. Plant performance is determined by characteristics or ‘traits’ which are partially genetically determined. Nevertheless, cultivars with the same genome (G) express different appearances or ‘phenomes’ in different environments (E) and under different management practices (M). Phenotyping the below-ground traits of plants is not straightforward, due to the opaque nature of soil.

Non-invasive geophysical techniques to study the root zone have substantially advanced in recent years.Their biggest potential lies in indirect monitoring of water depletion in the root zone, especially in time-lapse mode. To explore the potential of integrating geophysics in a field phenotyping platform, we first generated a range scenarios of soil moisture dynamics for different soils and grass cultivars. Then we generated ERT data from these distributions for selected electrode setups and then inverted them back to obtain conductivity distributions. In this way, we checked the performance of different electrode arrays to delineate root water uptake patterns in various realistic conditions.