Journal of Soil Science · 1992 · 381 citations · 9 references
AgricultureEarth SciencesSoil SciencesSoil PhysicsSoil ScienceSoil-water RelationsSoil HorizonsSoil MoistureSoil Physical PropertiesSoil Sensor CalibrationSoil TextureWater ContentMineral HorizonsOrganic HorizonsSoil CharacterizationSoil Moisture EstimationSoil Moisture Measurement TechniquesSoil Moisture ValidationVolumetric Water ContentVolumetric Water Content Calibration
Time‑Domain Reflectometry (TDR) is widely used by soil scientists to measure soil moisture. The study aimed to determine dielectric‑constant versus volumetric‑water‑content calibration functions for TDR across diverse mineral and organic soil horizons. An empirical calibration was performed on 11 mineral and 7 organic horizons, supplemented with capillary‑porous reference materials, to derive universal calibration functions. The results demonstrated distinct, reliable calibration functions for mineral and organic soils, enabling accurate TDR soil‑moisture measurements.
SUMMARY The paper is addressed to soil scientists who use Time‐Domain Reflectometry (TDR) technology to measure soil moisture. The practical aspects of the measurement calibration are discussed, and an empirical approach to establishing the existence of a universal calibration function is presented. Samples of 11 mineral soil horizons and seven organic soil horizons with different chemical and physical properties (including magnetic properties) were selected with the aim of determining their dielectric constant‐volumetric water content relationship as calibration functions for TDR soil moisture measurements. These samples were supplemented by other, soil‐like, capillary‐porous reference materials (montmorillonite, glass beads, washed sand and a sand from a C horizon). The study showed that a unique calibration function for mineral soils and another distinct calibration function for organic soils can be established.
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