To anyone whose interested. I realize some people dont choose to test their soil in this manner however others may be interested in learning how ... heres some good input on the subject.
To get a soil extract we recommend a similar method as we do for testing pH so that both EC and pH measurements can be taken at the same time.
- Gather a fresh soil sample in a plastic zip-loc bag. Try to get a profile from the top 6” of soil that the plants will grow in and take care not to contaminate the sample by touching with anything.
- Open the bag and let it air-dry for a few hours until it is mostly dried.
- Mix the soil in the bag to ensure a homogenous sample and then use a sieve with approximate 2mm spacing to remove any large soil clumps.
- Measure out ½ of a cup of the dried soil and put into a glass beaker.
- Measure out ½ of a cup of distilled water and put this into the glass beaker with the soil.
- Stir the mixture gently for 30 seconds. Do not mix to harshly as you may destroy the humus structure and the soil may give up elements that it otherwise would not do in nature.
- Let the soil-water suspension stand for 30 minutes.
- Stir water gently again before taking the EC measurement.
- Insert the EC meter into the beaker and swirl it gently around in the soil-water extract.
- After approximately 30-60 seconds or after the EC reading has stabilized, read the digital display on your meter.
Ideal EC Levels.
It is difficult to say what your ideal EC levels will be because there are so many variables affecting the EC level that it almost depends on your individual conditions which if you analyze over time, will give you a meaningful set of data based on the performance of your crops and the changes you have made to your fertility program.
As a general guideline however, a good soil EC level will be somewhere above 200 µS/cm and 1200 µS/cm (1.2 MS/cm).
Any soils below 200 means there is not enough nutrients available to the plant and could perhaps show a sterile soil with little microbial activity.
An EC above 1200 µS/cm may indicate too much high salt fertilizer or perhaps a salinity problem from lack of drainage so keep your EC within this range.
Also watch to see how EC changes over the growing season, you may see it increase as microbes are releasing more nutrients from the soil or you may see a decrease as your crops use up all the available nutrients. Either way you can fertilize accordingly.
You can read the full article on the website here ...
https://www.agriculturesolutions.com/resources/92-the-why-and-how-to-testing-the-electrical-conductivity-of-soils