The determination of cation-exchange characteristics of saline and calcareous soils.

An improved method for the determination of cation exchange characteristics suitable for saline, calcareous and gypseous soils has been developed. The soil is saturated with a LiCl solution buffered at pH 8,2 with LiOAc, followed immediately by leaching with Ca(OAc) 2 at pH 8,2. Na, K, Ca, Mg and Li are determined in the extracts by direct flame photometry and complexo-metry. The necessity of washing the soil has been eliminated by assaying the remaining excess salts as CI. Soluble ions are determined on a separate sample. The method can be used on non-saline or carbonatefree soils by adjusting the saturating and extracting solutions to pH 7.