Electrical Conductivity (Soil EC)

In agriculture, electrical conductivity is a measurement of how much electrical current soil can conduct. It is used as a way to map soil texture because smaller soil particles such as clay conduct more current than larger silt and sand particles. Veris, a manufacturer of EC measuring devices, decribes the process this way: One pair of coulter-electrodes injects a known voltage into the soil, while a second pair of coulter-electrodes measure the drop in that voltage. The result is a detailed map of the soil texture variability in the crop rooting zone. EC measurement is often used in place of grid sampling to define "zones" of variability in the field. These zones can then be overlaid with other types of field data to create prescriptions for fertilizer and lime application.