Soil thermal properties play an important role in predicting soil temperature for crop produc-tion, and in calculating the energy balance at the surface of the earth for predicting global climate changes. A single probe method (SP) for measuring thermal conductivity has been popular for over half a century. However, it needs to separately measure volumetric heat capacity. Recent developments of dual-probe heat-pulse techniques (DPHP) enable us to simultaneously measure thermal conductivity, A, volumetric heat capacity, pc, and thermal diffusivity, a, with a single probe. Three data extracting methods—the single-point method (SPM), a nonlinear model fit (NMF), and a weighted nonlinear model fit (WNMF)—for DPHP were compared with de Vries model for estimating thermal properties of loamy sand with a wide range of water contents (air-dry to 0.36 m3/m3). Performances of DPHP and SP were also compared with two distin-guished power input to a heater. Differences between estimated and modeled A and pc values were smaller in the following order : SPM< WNMF< NMF. Therefore, using WNMF is, in gener-al, recommended for estimating soil thermal properties. The DPHP technique was little affected by increases in contact resistance between soil and the heater probe surface due to evaporation made by the high power input, whereas SP was affected much.
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