ABSTRACT
Resistivity methods were among the rst geophysical techniques developed. The basic concept originated with Conrad Schlumberger, who conducted the initial resistivity eld tests in Normandy, France, during 1912 (Sharma, 1997). As an historical note, Conrad Schlumberger and his brother, Marcel Schlumberger, later founded the global oileld services company, Schlumberger Limited, which has been a leader in the development of borehole geophysical systems. Resistivity methods were originally employed in the petroleum and mining industries, and afterward found use in archeological, hydrological, environmental, and geotechnical investigations. Development of continuous resistivity measurement techniques in the late 1980s and early 1990s has transformed the basic resistivity method into an effective and efcient tool to assess soil conditions in large agricultural elds.
