In irrigation areas, one is often confronted with salinization problems. In order to acquire the necessary understanding regarding these issues, it is very important to check the salinity of the soil regularly. Also in examining ecosystems that are influenced by salt water (lagoons, etc), it is necessary that we know the salinity of the soil.

Eijkelkamp Agrisearch Equipment has developed a probe which enables its user to determine the salinity of a soil electrically. This probe is called the EC-probe (Electrical Conductivity probe).

EC-probe for salinity measurements, standard set for reading to a depth of 1 m

The EC-probe consists of a stainless steel bar, provided with a detachable handle. The bar is provided with a 10 cm graduation. Inside the actual probe, at the bottom of the bar, there are four electrodes, separated by a sealing ring and an insulation ring. To facilitate measurements with the EC-probe, proper contact (= low contact resistance) with the surrounding soil is necessary. To establish proper contact, first the gouge auger is used to make a pilot hole to the desired depth. The drilled out soil can be used as a reference sample to determine the calibration curve.

In every EC-measurement, the temperature of the soil stratum that is to be read must also be measured.
For this purpose, the tip of the probe is provided with a temperature sensor. Having measured the earth resistivity, the temperature correction factor is determined. The temperature coefficient can be read before the electrical conductivity is calculated.