Abstract
Understanding soil hydraulic properties is essential for efficient irrigation and fertilization management
in agricultural fields. Water diffusivity D(θ ) is a critical parameter in hydraulic properties and is known to be directly determined using the Bruce and Klute method (conventional method). However, the conventional method presents challenges in reducing experimental time and simplifying procedures. In this study, we proposed and compared a new horizontal infiltration experiment method using time domain reflectometry (TDR) soil moisture sensor, referred to as the TDR and fixed-location observation method, with the conventional method. The results showed that the determined D(θ ) values were of the same order, ranging from 0.01 to 10 cm2 s−1, across all methods, confirming that horizontal infiltration experiments using TDR soil moisture sensor are feasible. The TDR method successfully simplified the process and eliminated the cumbersome procedures of the conventional method. Moreover, while fixed-location observation method enabled quick and simple determination of D(θ ), it was found that high temporal resolution was required for accurate measurement.
