What is saline water and why is it considered saline?
Saline water has a relatively high concentration of dissolved salts. Salt is not just “salt” as we know it – sodium chloride (NaCl) – but can be dissolved calcium (Ca2+), magnesium (Mg2+) sulfate (S042-), bicarbonate (HC03-) and Boron (B). Salinity of water is referred to in terms of Total Dissolved Solids (TDS) and can be estimated by measuring Electrical Conductivity (EC), expressed as decisiemen per meter (dS/m), or less often in millimhos per centimeter (mmhos/cm) (the two measurements are numerically equivalent). EC is also reported in microsiemens or micromhos per centimeter, equal to 1,000 times dS/m. TDS is approximately related to EC by the following equations: TDS (parts per million, ppm or milligrams per liter, mg/l) = 640 x EC (dS/m) TDS (milliequivalents per liter) = 10 x EC (dS/m) Water is considered saline when it becomes a risk for crop growth and yield. The U.S. Department of Agriculture defines water with an EC greater than 3.0 dS/m as saline.
