ARS | Publication request: Gravimetric Determination of Inorganic Carbon in Calcareous Soils Using the Carbonate-Meter

Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: November 13, 2007
Publication Date: November 15, 2007
Citation: Rodriguez, J.B., Arriaga, F.J., Raper, R.L., Self, J.R. 2007. Gravimetric Determination of Inorganic Carbon in Calcareous Soils Using the Carbonate-Meter. ASA-CSSA-SSSA Annual Meeting Abstracts.

Technical Abstract: Organic carbon affects many important physical, chemical and microbiological soil properties. In calcareous soils, the inorganic carbon has to be measured and subtracted from the total carbon to obtain organic carbon. Our objective was to develop a gravimetric technique to quantify inorganic carbon using the Carbonate-Meter. The Carbonate-Meter can be prepared in any soil testing laboratory with the following components: one 50-ml Erlenmeyer flask, one 6-ml glass vial, and one number-1 rubber stopper with one hole. The inorganic carbon as carbon dioxide from two check soils were analyzed gravimetrically with the Carbonate-Meter, using 0.3000 ± 0.0300 g of fine soil, 4.0 ml of 50% HCl - 3% FeCl2.4H2O solution. Results after 5 hrs from initial reaction showed 100.55 and 99.73 % recovery, for the two check soils containing 0.728 and 2.57 % inorganic carbon, respectively. The gravimetric procedure is simple, inexpensive and has good accuracy and precision.