Modified Eaton's Methods for the Calculation of Gypsum and Leaching Requirement of Irrigation Waters in Arid Regions

Sodium adsorption ratio is superior to the percentage sodium values as an index of the sodium and alkali hazards of the irrigation water. In calculating the gypsum requirement of irrigation water, instead of converting them to 70 per cent sodium as envisaged in the formula proposed by Eaton, they are converted to the Si or S₂ class.