EC Mapping

Soil EC Mapping is a way to measure soil texture. The EC (electrical conductivity) of a soil correlates strongly to soil particle size and texture. Sandy soils have low conductivity, silts have medium conductivity, and clays have high conductivity. Soil EC maps define exactly where soil texture changes in a field. This information can be used to do many things. To name a few, you can set:

  • Fertility Management Zones
  • Soil sampling locations
  • Variable Rate Seeding (VRS)
  • Variable Rate Nitrogen (VRN)
  • Variable Rate Irrigation (VRI)
Soil EC mapping your field can be done in the spring before planting, or after you've harvested your crop.

EC Mapping provides a starting point to begin to manage the soil variability that exists in fields. Different soils have different capacities for producing crops. Knowing the texture of your soils is a starting point to optimizing your inputs and maximizing your yield. Together with your Valley Agronomics Crop Advisor, you can create a plan to Variable Rate Fertilize, Variable Rate Seed, and Variable Rate Irrigate.



We bring our Dualem 1S Sensor to your field. This sensor measures electrical conductivity at two depths: 1 meter and 1/2 meter. The sensor is placed in a plastic sled to prevent any interference from metal.

Our EC Sled is pulled by a Polaris Ranger across your field. As we go, the sensor sends readings to a computer in the Ranger.

As we drive, our Trimble guidance display provides GPS locations that are referenced to the the readings from the Dualem 1S sensor with decimeter accuracy. While EC Soil Mapping your field, we also collect Elevation data. Elevation data is another layer of information that can be useful in managing variability within a field.


Knowing the texture makeup of your field has several advantages. Soil texture affets:
  • Water-holding capacity
  • Cation exchange capacity
  • Drainage
  • Nutrient leaching
  • Nutrient retention & supply
How soils hold, use or lose their nutrients is strongly related to soil texture.