Fig. 8. Temporal development in the maximum absolute difference between the actual relative bulk soil electrical conductivity (EC_b) distribution and the theoretical TDR-measured relative EC_b distribution (Maximum Relative EC_b) for (a) the three-rod probe in Fig. 1a compared with two-rod probes with varying probe rod separation (D) and (b) two-rod probes with constant D, but various rod diameter (B). Calculations were based on soil data ( and D_p) obtained in the diffusion experiment (Method II) carried out at = 0.256 m³ m^-3.