Utilizing gridded soil sampling and electromagnetic induction to map salinity in coastal farm fields of North Carolina, USA

作者：J. Janson, M. Ricker · 发表于：Environmental Earth Sciences · 年份：2026 · DOI：10.1007/s12665-026-12841-4 · 被引用次数：1

Saltwater intrusion (SWI) is intensifying along the Inner Banks of North Carolina due to rising sea levels and increased nuisance flooding. Coastal agricultural fields, particularly those with artificial drainage networks, are vulnerable to overland flow, resulting in variable patterns of soil salinization driven by microtopography, texture, and hydrologic connectivity. Heterogeneity challenges monitoring efforts, necessitating validation of non-destructive tools for salinity mapping across large areas. This study evaluated the efficacy of electromagnetic induction (EMI) for mapping salinity across high-carbon agricultural fields in Hyde County, North Carolina (NC). A DUALEM-1 H sensor was used to conduct EMI surveys at four depths (0.3, 0.5, 0.8, and 1.6 m), to generate georeferenced apparent electrical conductivity (EC) maps using ArcGIS. EMI-derived EC values were validated against in-field readings from a portable EC kit and laboratory EC data from the NC Agronomic Services Lab. Results demonstrated that EMI is a robust tool for the characterization of salinity patterns in high-carbon mineral soils with clay-enriched subsoils (Alfisols). Statistically significant correlations were observed between lab EC values and both field kit EC (R2 > 0.88) and EMI EC at 0.3 m depth (R2 > 0.76). Though EMI correlations varied with depth due to water and clay content, it reliably detected salinization at agronomically relevant depths. The integration of EMI surveys with field EC kits o...