Fig. 8. Temporal development in the maximum absolute difference between the actual relative bulk soil electrical conductivity (ECb) distribution and the theoretical TDR-measured relative ECb distribution (Maximum 
Relative ECb) 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 Dp) obtained in the diffusion experiment (Method II) carried out at = 0.256 m3 m-3.
