Determination of Water Content in Clayey Red Soil Using Techniques Based on Measurement of Dielectric Constant

摘要

Two time-domain reflectometry (TDR) systems and a new impedance measuring instrument, Thetaprobe, which are based on determination of soil dielectric constant, were used to measure water content of clayey red soil to evaluate the accuracy of these instruments. The results indicated that these instruments should be carefully re-calibrated before being applied in clayey red soil. With a new calibration curve fed into one of the TDR systems tested, Trase system, the measured data compared well with those by standard oven-drying method.