ABSTRACT
There are a number of instruments available for kinematic soil mapping by geoelectrical methods. Thus, a potential user might ask him-or herself, which is the appropriate instrument, what does it measure, and how accurate can the measurement be? What is measured is largely inuenced by the underlying measuring principle. From theory, we know that the depth response curves of geoelectrical measurements could vary depending on the layering of conductive and resistive structures (Dabas and Tabbagh, 2003). It is assumed that the galvanic contact resistivity (GCR) and the electromagnetic induction (EMI) methods react different on soil layering. Most of the instruments used for soil mapping in agriculture are based on one of these two principles. A third method, based on capacitively coupled resistivity, has rarely been used in agricultural practice up to now. Thus, we will focus on GCR and EMI instruments.
