Irrigation water quality
If you have to irrigate it pays to understand what is in your water. Unless you are using rain water, chances are you have a host of soluble minerals and compounds you are delivering along with the needed moisture. In some cases these dissolved minerals can cause a host of problems for your soil and plants.
Even if you are using municipal water, but especially if you are on a well, it pays to get a water test. Logan Labs offers a standard water test and an extended test for irrigation water suitability.
As with all tests, the real question is how to interpret them. We have gone through the water test terminology in detail and have written an explanation of how to interpret a water test report.
Some ground water is high in sodium with respect to calcium and magnesium and can cause problems with soil structure in expansive clay soils especially. The sodium causes the clay particles to separate and clog the pore structure of the soil, creating crusting and hard soils.
High amounts of dissolved minerals or “salts” as they are referred to (“salts” are not just sodium and chloride) can limit the growth and germination rate of certain plants.
Water can deliver substantial amounts of necessary elements like calcium and magnesium as well.
Of particular interest is the level of bicarbonates and carbonates in the water. These can interfere with the availability of nutrients to the plant and can even block utilization of iron in the plant. Bicarbonates in conjunction with calcium will create deposits of calcium carbonate, lime, and plug drip emitters. It can leave a white residue on fruits and veggies that consumers may think is pesticide residue.