EC index in coir growing medium
We already know that in the soil, the growing medium has a number of criteria that affect the growth of plants and often includes common criteria such as pH, salinity (understood as factors directly related to the growth of plants). EC), acidity and nutrient content in the soil that plants can exchange and absorb. Each type of crop will require certain indexes or index correlations.
Among the indicators in the soil, or the medium, or the growing solution, you will often hear pH and EC. These are probably the 2 most important indicators.
Learn about Tropicoco pre-mixed coir substrate. This is a well-treated coir product with a very low EC <0.5ms/cm.
EC is a very important indicator in growing media, especially coir. So let’s find out what EC is and why it’s so important.
EC is the electrical conductivity of a substance, it is an acronym for Electrical Conductivity. The EC index measures the electrical conductivity of a solution or a substance (possibly in a growing medium).
In solution, water used in hydroponic agriculture, in automatic irrigation or fertilization systems contains many dissolved salt molecules, it can exist as positive ions, negative ions, or cations, anions… The existence of these salt molecules in solutions (the moisture of the substrate) makes it capable of conducting electricity.
This means that in solutions with a lot of salt, the EC will be high, and in solutions with less salt, the EC will be lower.
Therefore EC is an important indicator to determine the total salt content of the solution, but it does not help us to determine the ionic composition of the water. It is understandable that we can determine the EC index in the substrate (or the substrate after hydration) is 0.5ms/cm, but we do not know how much Potassium (K+) or Na+ ions are present in the solution. .
There are some elements that act like fertilizers like Urea that do not increase or decrease EC. Specifically, even if the Urea content is increased, the EC index will not change.
To measure EC, we can use a measuring pen to determine the EC index in the nutrient solution, the unit of EC is mS/cm (milisiemens/cm) or μS/cm (microsiemens/cm). Convert 1 mS/cm = 1,000 μS/cm.
Back to the growing coco peat growing medium, the lower the EC index, the better the salt treated coco peat. And readings below or above 0.5mS/cm are standard readings. For plants that require good handling of salinity, an EC value of < 0.5 mS/cm is required.
Classification of soil salinity by conductivity (EC) (Maas and Hoffman, 1977)
|Sensitivity to salt in the soil of plants
|The plant is very sensitive
|Very little salty
|Plants are moderately susceptible
|0.95 – 1.90
|Poor salt tolerance
|2.0 – 4.5
|Moderate salt tolerance
|4.6 – 7.7
|High salt tolerance
|7.8 – 12.2
|Too salty for the tree
Some common types of coconut fiber growing medium: