What is the classification of irrigation water having the following characteristics: concentration of Na, Ca and Mg are 24, 5, and 3 milli-equivalents per litre, respectively?

Concept:Sodium-ion in small amounts is good for plants. But excess sodium ion CREATES the problem for both plant and soil. Excess sodium contributes to salinity and it is toxic for some sensitive crops.Soil with high sodium CONTENT becomes very plastic in nature in the wet stage, which shows low permeability and poor aeration.This excessiveness of sodium ion is MEASURED in terms of sodium absorption ratio (SAR).\({\rm{SAR}} = \frac{{\left[ {{\rm{N}}{{\rm{a}}^ + }} \right]}}{{\sqrt {\frac{{\left[ {{\rm{C}}{{\rm{a}}^{2 + }}} \right] + \left[ {{\rm{M}}{{\rm{g}}^{2 + }}} \right]}}{2}} }}\)Where,[Na+] = concentration of sodium ion in milli-equivalent per liter[Ca2+] = concentration of calcium ion in milli-equivalent per liter[Mg2+] = concentration of magnesium ion in milli-equivalent per literSARType of water0-10Low sodium10-18Medium sodium18-26High sodium>26Very high sodiumCalculation:Given,Na+ = 24, Ca2+ = 5, and Mg2+ = 3\({\rm{SAR}} = \frac{{\left[ {{\rm{N}}{{\rm{a}}^ + }} \right]}}{{\sqrt {\frac{{\left[ {{\rm{C}}{{\rm{a}}^{2 + }}} \right] + \left[ {{\rm{M}}{{\rm{g}}^{2 + }}} \right]}}{2}} }}\)\({\rm{SAR}} = \frac{{\left[ {{\rm{24}}{{\rm{}} }} \right]}}{{\sqrt {\frac{{\left[ {{\rm{5}}}\right] + \left[ {{\rm{3}}{{\rm{}}^{ }}} \right]}}{2}} }}\)SAR = 12Hence the classification of irrigation water is medium sodium water.