Department of Soils, Haryana Agricultural University, Hissar, 125 004, Haryana
*Laboratory of Soils and Fertilizers, State Agricultural University, Wageningen, The Netherlands
A linear relationship between ionic strength (I, M/I) and electrical conductivity(EC, mmhos/cm at 25°C) based on 54 soil extracts was given by the equation, J=0.0114 EC+0.0055; (r=0.996)
The regression coefficient decreased with increasing ionic strength of the extracts. A nomogram depicting a relationship between electrical conductivity, ionic strength, ionic charge and activity coefficients was drawn based on the Davies equation and the above expression, to facilitate direct reading of the activity coefficients from the electrical conductivity values.
Ionic strength, electrical conductivity, activity coefficients
