Spatial variability of soil physical and chemical properties is a fundamental element of site-specific soil and crop management. Since its early implementation in agriculture as a method of measuring soil salinity, the acceptance of Apparent Electrical Conductivity (ECa) in agriculture has been popular as a method of determining the spatial variability of soil physical and chemical properties that influence the ECa estimates. It was the objective of this study to examine the spatial-temporal stability of ECa estimates in selected Eastern Corn Belt soils. By employing spatial statistics to the ECa estimates, this study was able to determine that on a field scale, ECa estimates at 0-30 and 0-90cm depths were variable at distances that ranged from 25 to 115m. Only one soil mapping unit tested significant at 0-30 cm while there were no significant results between individual soil mapping units and ECa at 0-90 cm over the five years data that were collected. ECa estimates were also collected in west-central Indiana on small plots (6x42 m) of prairie and forested soils on a weekly basis over a period of 12 -13 weeks to assess spatial-temporal ECa estimates at 0-30 cm depth. Spatial autocorrelation distance for the ECa at 0-30cm depths for the six sub-fields varied from 2 to 10m. Some weeks were significant for soil moisture, organic matter or K but the results were not consistent using either the ordinary least squares (OLS) or spatial process models, and the causality relationship could not be established as they were not consistent. This study concludes that apparent electrical conductivity (ECa) does not provide consistent results for the measurement and/or assessment of soil moisture content, organic matter and potassium.