Measurement of Specific Surface of Soils

There are a number of methods for determining the specific surface of soils. The different methods for finding the surface area of soils have been reviewed and critically discussed. A laboratory study was carried out using eight sandy and silty soils for comparing the specific surface values determined by the analytical, empirical, air permeability and glycerol retention methods. It has been observed that all the methods other than the glycerol retention method give very low values of surface area and hence are not suitable even for the sandy and silty soils free from claly having internal surface. However, it is suggested that the empirical method, being the simplest and the easiest, may be used for sands by suitably modifying the constants of multiplication as suggested in this paper. Glycerol retention method is most suitable for all soil types.