Soil Profile Investigation with Integrated Ground-penetrating Radar and Electromagnetic Induction Techniques

• Main Authors: Pathirana, S., Galagedara, L., Lambot, Sébastien, Cheema, M., Krishnapillai, M., CSBE/SCGAB AGM and Technical Conference 2024 on “Engineering Responses to Wicked Problemsâ€
• Other Authors: UCL - SST/ELI/ELIE - Environmental Sciences
• Format: Conference Object
• Language: English
• Published: 2024
• Subjects: Newfoundland
• Online Access: http://hdl.handle.net/2078.1/289999; https://doi.org/10.13140/RG.2.2.31413.49128

Near-surface geophysical techniques, including ground-penetrating radar (GPR) and electromagnetic induction (EMI), have become alternative methods to estimate soil properties and state variables (soil information) in agricultural landscapes to support precision agriculture. Understanding the soil profile is crucial for interpreting geophysical data to accurately estimate soil information. Traditionally, soil coring and open pit excavation provide valuable insight into soil profiles, although they are tedious and destructive. This study aims to evaluate the effectiveness of an integrated GPR-EMI technique for understanding soil stratification and subsurface distributions within a podzolic soil site in Newfoundland. Soil samples were collected for basic soil properties (texture, gravel and organic matter percentages, bulk density) from five locations within a 12 x 18 m² area. Geophysical data were collected using a multi-coil EMI sensor and a 500 MHz frequency GPR system. EMI depth inversions, GPR depth slices, and 2D profiles were prepared to observe distinct soil stratification patterns in the soil profile. Analysis of soil sampling (0-0.60 m depth) and geophysical data (0-1.8 m depth) exhibited consistent patterns reflecting the changing soil profiles with depth. Basic properties assessed for shallow soil layers (0-0.30 m) showed a significant (p<0.05) difference from deep layers (0.30-0.60 m). Similarly, a distinct layer was found from GPR and EMI, around 0.3-1.4 m depth. The integrated technique confirmed each method's findings and revealed insights into the spatial variability of soil density, electrical conductivity, and structural changes in the soil profile. This non-destructive approach can advance precision agriculture by facilitating more accurate soil management strategies.