1 CALIBRATION OF SOIL MOISTURE PROBES IN SALINE CONDITIONS

ABSTRACT: Two soil moisture probes from Decagon Devices were calibrated to measure volumetric water content and salt concentration in the soil's moisture. The probes used were the EC-5 and EC-10 models, and the soil used has a USCS classification of SP or poorly graded sand. The EC-10 probes were found to work well for determining the salt concentration, in parts per million, of the soil if the volumetric water content is already known. The EC-5 probes also proved useful for the determination of salt concentrations, but the EC-10 probes proved to be more accurate. Soil-specific calibration curves were developed for both probes for use in saline soils at a range of volumetric moisture contents. Both probes were found to be useful for determining the volumetric water content of soils with no salt present. The probes have each have a very similar calibration curve in non-saline soils so a singl