Electric resistivity of some soil complexes

The electric resistivity of some soils was investigated from room temperature to ∼700 K. The studied soils represent Assiut valley desert soils (S 1 ) and farmland of Assiut University soils (S 2 ). The temperature dependence of the electric resistivity is discussed; it was found to decrease with increasing temperature. The results indicate that the electric resistivity depends on ions and only to a small extent on electrons. Also, the electric resistivity values lie in the range of insulating materials. The results are supported by scanning electron microscope (SEM) analysis and a mechanical analysis.