INTERPRETATION OF ELECTRICAL-RESISTANCE SOIL MOISTURE DATA FOR A FREEZE-THAW ENVIRONMENT

Abstract
The value of electrical-resistance measurements from soil moisture blocks in a freeze-thaw environment can be enhanced by laboratory calibration in the subzero temperature range to provide a measure of unfrozen water contents. Laboratory studies show that, in the temperature range of incipient freezing and thawing (−3 to 0 C) electrical resistance as measured with Colman fiberglas resistance blocks is independent of temperature. At temperatures less than −3 C, electrical resistance is dependent upon both the nature of the porous medium and temperature, but is independent of the total water content of the soil-water system. Results from the laboratory investigations are extended to the interpretation of field measurements of electrical resistance for a soil profile at Calgary, Alberta, Canada.