Abstract
Estimates of soil properties such as Cation Exchange Capacity (CEC), water content, grain size characteristics, and permeability are important in geotechnical engineering, water resources, and agriculture. We develop a non-intrusive approach to estimate these properties in the field using spectral induced polarization (SIP) tomography. This geophysical method provides information about the frequency dependence of the complex electrical conductivity of porous media. Using 18 soil samples collected from a Bordeaux vineyard, we first conducted a laboratory study using SIP over the frequency range 10 mHz-45 kHz. The laboratory data were used to confirm the accuracy of a recently developed dynamic Stern layer petrophysical model. The results are consistent with published values from previous works using soils. A comparison was made by comparing the field complex conductivity spectra and the experimental data at two locations where core samples were obtained. The model was then used in concert with field data to image the spatial distribution of CEC, water content, permeability, and mean grain size along a vineyard transect. For clay and sandy textures found in the field, measured and estimated CEC agree rather well (from 6 to 40% discrepancy). Our approach provides an efficient way to estimate important soil properties in a non-invasive manner, in high resolution, and over field-relevant scales of the critical zone of the Earth.
Original language | English |
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Article number | 115380 |
Journal | Geoderma |
Volume | 403 |
DOIs | |
State | Published - Dec 1 2021 |
Externally published | Yes |
Funding
We thank the INTERREG SUDOE project “Soil Take Care” for funding. and the Chateau “La Louviere” in France for access to their domain. The authors are grateful to C. Arbogast for his help in the field. S. Hubbard was supported through the Watershed Function Scientific Focus Area funded by the U.S. Department of Energy, Office of Science, Office of Biological and Environmental Research under Award Number DE-AC02-05CH11231. The data are provided in DRYAD (https://doi.org/10.5061/dryad.n02v6wwvs). We thank the Editor, Dr. Cristine Morgan, and three anonymous referees for their very useful comments.
Keywords
- Cation exchange capacity
- Chargeability
- Critical zone
- Grain size
- Induced polarization
- Soil
- Tomography
- Water content