The use of geophysical methods to study processes in dryland agro-ecosystems


Overview: The study of the subsurface is increasingly making use of electrical methods to characterize the subsurface, primarily relying on the electrical conductance of water. While this relatively simple approach is already being downscaled from geological structure to environmental and agricultural scales, there are still many knowledge gaps and opportunities to be explored. In the following we will explore these opportunities to identify current and future knowledge needs, with respect to soil water, soil-water-plant interaction, and applied use of these methods.


The study of bulk properties of soils dates to the 1940’s and even before, initially with respect to geological structure and mineral exploration, and more recently to environmental and agricultural reasons. In this session we will explore the current trends in the use of geo-electrical methods in soil and agricultural exploration, starting from electrical resistivity tomography (ERT) of agricultural fields, through induced polarization (IP) methods to explore soil chemical composition, ending with passive electrical signatures such as self-potential (SP) associated with redox reactions in the subsurface. In parallel we will also look at environmental applications of geo-electrical methods.


In recent years the idea of using the more advanced geo-electrical methods to understand phenomenon such as root uptake or tree trunk structure gaining momentum. But in parallel, more basic methods such as ERT is increasingly being used in smaller scales to understand the spatial patterns of water and nutrients in the soil-plant environment. This session will try to look at these processes from both the applied and the theoretical points of view.