Sodium is one of the most studied elements because of its toxic effects to soil texture and crops. High concentrations of sodium disperses soil colloidal particles, rendering the soil hard and resistant to water penetration. The build-up of osmotic pressure in soil due to high sodium concentration hinders water absorption by plant roots. High amounts of sodium can be mitigated with the distribution of gypsum directly on soil or as an additive to irrigation water. The Hanna Instruments test kit determines Sodium Hazard in irrigation water by calculation of SAR (Sodium Absorption Ratio) in relation to Calcium and Magnesium concentration. The kit is supplied with our DiST®4 Conductivity Tester, to quickly determine the conductivity of irrigation water. The kit's manual also supplies information about practical actions to take from the results obtained.