Salt Affected Black Soils: Chemical Characteristics and Sodium-Divalent Cation Exchange Relationships

The chemical characteristics of salt affected soils in the Agricultural Research Station, Siruguppa (Karnataka) were investigated. The electrical conductivity and concentration of ions, except sulphate, decreased with depth. The ESP values were found to be much higher compared with those predicted from the ESP-SAR regression equation of the U. S. Salinity Laboratory. There was better agreement between the predicted and actual ESP values when allowance was made for ion association between sulphate and calcium-magnesium and also after making correction for activity in the calculation of SAR.