A system for measuring soil electrical conductivity having a support, a plurality of soil engaging contacts (e.g. coulters) mounted to the support, at least one probe, and a processor. Current is provided through the soil and then measured. The voltages measured between respective opposed pairs of contacts are used to calculate the soil electrical conductivity of the soil within first, second, and third depth ranges. Each probe is selectively inserted within the soil and is configured to determine the soil electrical conductivity of the soil within the first, second, and third depth ranges. The processor correlates the calculated soil electrical conductivity of the soil within the first, second, and third depth ranges with the soil electrical conductivity determinations of the probe. Methods of determining and imaging soil characteristics and applying those characteristics to a crop model are included.