An examination of procedures for determining carbonates in soils and related materials

Abstract

A number of procedures were tested for determining carbonate-C in soils and limestones, using a simple technique for digesting and collecting the CO2, previously described by the author 10 . Some of the procedures appeared suitable for removing and quantifying carbonate-C prior to the determination of organic-C. Depending on the digestion solution and the length of treatment, between 0.25 and 0.68 % of the organic-C in cultivated mineral soils was released as CO2 during the digestion, and thus included in the figures for carbonate-C.The study includes furthermore, an examination of the effects of particle size and the length of the heating period on the rate of dissolution of calcite and dolomite. A semi-quantitative EDTA extraction procedure is described for separation of these minerals in limestones.