The Modifying Effect of Electrolyte Concentration on the Effect of Exchangeable Sodium on Some Soil Physical Properties and Sodic Soil Reclamation

The modifying effect of electrolyte concentration varying from 0 to 40 m.e./l on diffusivity-water content relationships of a soil of varying exchangeable sodium percentage (ESP 5 to 70) investigated in a laboratory study resulted in increases in soil-water diffusivity with increases in the concentration of electrolytes present in irrigation waters. The increase was more at higher water contents and in soils of higher ESP. The weighted mean diffusivity increased by 2.8, 3.1, 20, 40 and 164 times for soils of ESP 5, 14, 22, 30 and 70, respecctively, when the electrolyte concentration of permeating water was increased from 0 to 40 m.e./l. In field tests reduction in soil ESP due to leaching was higher as well as effective to a greater depth when waters of higher electrolyte concentrations were employed. The study brings out the relative ease with which sodic soils can be reclaimed when irrigation waters of varying electrolyte concentrations are used.