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DESCRIPTION
EC in agriculture
EC stands for electrolytic conductivity, or the ability of a solution to conduct an electric current.
Current travels efficiently through water with high levels of salt present (high EC), and less so
through pure water (low EC). EC indicates how much dissolved salt is in a given sample. That's why
EC is also referred to as TDS (total dissolved solids). All nutrients are salts, so EC is a measure of
your total nutrients. Knowing your EC levels will help in plant production and monitoring of inputs.
Monitoring the EC of aqueous solutions is fairly simple.
You calibrate the probe in a known standard, then submerse the sensor into the liquid.
To use EC to check fertilizer levels, take an EC reading of a precise mixture of your fertilizer and
irrigation water in the desired concentration. You can check your fertigation water at any point
along the system. Its EC should match your sample. If it doesn't, check the injectors, valves and
nozzles in the system for blockage or other problems.
Always check the EC of your water first, and subtract that number from the EC reading of your
solution to determine your fertilizer concentration.
Another way to determine the output of your fertilizer injector is by measuring the electrical
conductivity (EC) of the dilute fertilizer solution. You can get a good estimate of the fertilizer
concentration by measuring the EC of the solution by using a EC meter.
Be sure to calibrate your monitor before use and be sure to subtract the EC of your clear water from
the fertilizer reading. Compare the corrected value for the EC of your fertilizer solution to that listed
on the fertilizer bag for the ppm N you intend to be apply.
During the crop cycle, especially for short‑term crops like bedding plants, you should monitor the EC
of your fertilizer solution to check that the injector is working properly. The fertilizer label may have
the EC of several concentrations of the diluted fertilizer.
For example, the EC of 100 ppm N, is 0.65 mS/cm.