We combined the radiative transfer approach to simulate L-band brightness temperatures at 1.4 GHz with a hydrological simulator (HYDRUS 1D) and a global optimization routine SCE-UA to estimate the Mualem van Genuchten (MVG) soil hydraulic parameters from time-lapse L-band brightness temperatures and in situ soil moisture measurements at different depths. The measurements were collected from a bare soil plot, prepared after ploughing. First, we briefly described the coupled inversion procedure and compared the results with measured brightness temperatures and in-situ soil moisture data. Second, estimated soil hydraulic parameters were compared with laboratory derived ones. The results suggest that the proposed method is promising for the effective characterization of the soil hydraulic properties and the determination of soil moisture within the top soil layer.