Department of Chemistry, Himachal Pradesh University, Simla-171 005 Manuscript received 30 April 1981, revised 14 September 1981, accepted 10 December 1981 The phenomenological permeation coefficients for water and aqueous solutions of ammonium nitrate, ammonium sulphate, ammonium phosphate at different concentrations and at 35�� were determined for a soil membrane of known thickness and water content. The results have been interpreted in terms of the principles of non-equilibrium thermodynamics. It has been found that the permeation coefficient for water is than that of the ammonium salt solutions. Frictional coefficient between membrane matrix and water has been evaluated and its dependence upon the solute concentration has also been discussed. The effect of concentration of the electrolyte solution on the radius of pore of the membrane equilibrated with the electrolyte solution has also been discussed.