Sodium Absorption Ration (or SAR) is one of the most studied elements because of it's toxic effects to soil and crops.
High concentrations of sodium disperses soil colloidal particles, rendering the soil hard and resistant to water penetration, which in turn leads to rain run-off after prolonged dry periods and makes flooding and crop damage more likely.
The build up of osmotic pressure in soil due to high sodium concentration hinders water absorption by plant roots.
To combat high sodium concentration in soil, gypsum can be added directly to the field, or as an additive to irrigation water.
Hanna Instruments manufacture a chemical test kit designed specifically for Sodium Absorption Ratio calculation.
The test kit comes complete with a pocket digital conductivity meter and determines Sodium Hazard in water by calculation of SAR in relation to Calcium and Magnesium concentration.
