Soil Electrical Conductivity (EC) is a measurement of the total soluble salts level in our soil and is a key indicator of soil health. The Soil EC test is a simple, quick and inexpensive method which farmers can use to examine their soil health status. Soil EC shows the level of the available water-soluble nutrients in the soil such as nitrate nitrogen and can be used indirectly for fertilizing decisions. In irrigated lands, EC is used to assess the salinity level in the soil, and to monitor and manage salts in the irrigation water.
When we measure soil EC, we are actually measuring the ability of the soil-water matric to transmit electrical current, and the EC values are presented with the unit of mS/cm. Siemen is the SI unit for electrical conductance.
Soil EC can be measured in different ways and the results from these measurements can be converted from one to another through empirical or theoretical equations:
- Pore water EC: The electrical conductivity of the water in soil pores. To measure the pore water EC, soil pore water needs to be extracted. The EC is then measured in the sample.
- Bulk EC: The electrical conductivity of the bulk soil matrix and this includes all three phases in the soil (soil, water, and air). Bulk EC can be measured by using in-situ EC sensors or electromagnetic remote sensing technologies.
- Saturation Extract EC: The electrical conductivity of the water extracted from saturated soil paste. This is the traditional method to measure soil EC. Due to the intensive labor involved in this measurement, most laboratories will measure EC in the 1:1, 1:2 or 1:5 extracts.
Solum Soil EC Test
At Solum, we offer soil EC test from the 1:3 extraction method and convert the results to 1:1 extraction method through regression. The newly implemented EC robot at Solum provides us with the abilities of high sample throughput and better quality control. We test EC for both soil and water samples.