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 author¹⁰. 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.