A soil moisture mapping based method for transferring soil for an earthworks construction project includes outputting signals based on soil moisture data and position data indicative of a location within a cut area or a fill area of the soil. One such circuit includes a charge pump circuit including a first transistor, a high-voltage switch circuit, and a cut-off switch circuit arranged to reduce leakage current from the charge pump circuit. The DC-DC converter further includes a control unit which turns the switching element for regeneration on a predetermined time period after the timing of turning the primary side switching element off. At least a portion of the titanium metal layer is eventually converted to titanium silicide, thus providing an excellent conductive interface at the surface of the diffusion region. An electric field developed between the electrodes is defined as a moisture detecting region.