What does soil electrical conductivity measure?
Conductivity is a measure of the ability of a material to transmit (conduct) an electrical charge. It is an intrinsic property of the material just like other material properties such as density or porosity. Geo-referenced soil EC data is a map showing how the various soils in a field differ in their ability to conduct electricity. The value of a soil EC map in agriculture is that it’s a rapid, low-cost, and effective surrogate measurement of soil properties, such as soil texture–the relative amount of sand-silt-clay. To collect 50+ soil samples/per acre and have them lab analyzed, would be cost-prohibitive. Yet a Veris EC system collects that many data points per acre, and can produce an accurate map of soil texture variability for a few dollars/acre. The clay content map from Iowa at left was generated using 24 lab-analyzed samples from a 40 acre (16 ha) field. The Veris 3100 mapped the same field in less than one hour–producing the map on the right.
