Three Dimensional Variability of Soil Electrical Conductivity Based on Electromagnetic Induction Approach

In the present study, 56 soil apparent electrical conductivity(ECa) profiles, which inversed by the procedure that combine the EM38 linear model with Tikhonov regularization from aboveground EM38 measurements, were selected as the datum source of 3D spatial variability. First, the horizontal and vertical variogram were analyzed, respectively. Then, Combining the variograms, a 3-D an isotropic variogram was constructed which consisted of an isotropic nugget effect and three spherical models. 3D ordinary kriging method was used to predict the three dimensional spatial variability of ECa. Plume model was used to present ECa spatial distribution. The contour map of ECa, which with a high salinity level in the east corner and low salinity level in the west and northern corner of the field. In addition, the salinity increased with the increase of the soil depth at the vertical direction. Land use planting can be made more accurate for taking the salinity beneath a certain depth into account.