Solutions for high-salinity irrigation water or soils — III
Desalinate Your Water
Another way to face salinity in your irrigation water is to purify that water by a process called Reverse Osmosis.
Osmosis is a natural process where the water flows from a less concentrated area to a more concentrated one through a semipermeable membrane until the concentrations are equal. Reverse osmosis does the opposite: it forces water from a salty or impure area (very concentrated) to a clean area (less concentrated). This is achieved by applying a high pressure to the water that forces it to pass through the membrane even though, without the pressure, it would naturally flow in the other direction. Doing this, you end up with purified water on one side and brine on the other.
But this doesn’t end here ! Totally pure water is harmful for plants. We need irrigation water with a certain concentration of salts and nutrients.
To reach this, we can mix a bit of salty water with the pure one. The only condition is that the conductivity has to remain under 1000 ÎĽS/cm to be safe for plants.
To calculate the proportions of your mix, just follow these simple steps:
Proportion=
Here’s an example: we have 3000 μS/cm salty water and want to reach a final 600 μS/cm water.
We calculate:
..which is equal to 1/5. That means 1/5 of the mix is made of salty water and 4/5 of the pure water. Reformulating, for 5L of final water, we will mix 1L of salty water and 4L of pure water.
In that way, you are sure to use the best quality water for your plants!
When performing Reverse Osmosis, for every liter of clean water produced, around 250mL of brine remains, which needs to be managed. At the Orchard of Flavours, we built an evaporation tank (see below) to collect the salt left behind as the water evaporates. Another option is to use the brine to grow salt-tolerant plants!
Simply check its salinity and choose the right species. Visit our database for guidance on salt-tolerant plants. Keep in mind that many other plants that thrive in these conditions aren't necessarily edible but can be beautiful ornamentals.
Evaporation tank
You can find here a link to Ecosoft, the leading brand in Reverse Osmosis: https://www.ecosoft.com.
If you’re dealing with high salinity in your land, now you know that desalinating your water is one of the solutions available to you. But it’s not the only one. Keep scrolling to find more content in this Research series.
This article was compiled by Miguel COTTON & Angela DUZAN. If you have any questions or suggestions, do not hesitate to contact us. Please write us anytime at miguel@orchardofflavours.com
Interested in more content relating to the growing issue of soil salinity and its effects on plants and soils, as well as solutions? This article is part of our Research series "Salinity and Edible Plants":
