%0 Research Notes %T Calibration of time domain reflectometry (TDR) for soil moisture measurements in cultivated peat soils %A Myllys, Merja %A Simojoki, Asko %D 1996 %J Suo - Mires and peat %V 47 %N 1 %U http://suo.fi/article/9750 %X Time domain reflectometry (TDR) is a relatively new technique for measuring soil water content. It is based on measuring the apparent dielectric number (Ka) of the soil from the propagation velocity of an electromagnetic pulse travelling in the soil. Soil water content is then calculated from the apparent dielectric number. In this study, an empirical relationship between the apparent dielectric number and the volumetric water content was established for cultivated peat soils in the laboratory. A third-degree polynomial described the relationship with a coefficient of determination of 0.980 and a standard deviation of 0.027 m3m-3. The relationship can be used to measure water content in typical cultivated Sphagnum and Carex peat soils in the range usually prevailing in the field, i.e. 0.3-0.8 m3m-3. Key words: dielectric number, water content