ESTABLISHING SOIL ELECTRICAL-CONDUCTIVITY - DEPTH RELATIONS FROM ELECTROMAGNETIC INDUCTION MEASUREMENTS

Principles of electromagnetic induction (EM) and field calibration approaches are discussed as they pertain to the application of EM to soil systems for the purpose of deriving soil electrical conductivity - depth relations. Evidence is provided to support the utility of EM-derived estimates of ECa-depth relations. Limitations of using electromagnetic induction to determine ECa for discrete depth intervals through the soil are discussed. Current research designed to increase the accuracy of ECa-depth determinations by dealing with the spatial variability problem associated with salinity in soil and by mitigating some of the inherent limitations of the calibration approaches is described. © 1990, Taylor & Francis Group, LLC. All rights reserved.