Abstract
A simple titrimetric method is described for the estimation of Ca and Mg carbonates in soils. It involves the determination of acid-soluble Ca and Mg of the carbonate phase after the removal of soluble and exchangeable cations by ammonium acetate (NH 4 OAc). Twenty-six tropical soils, which contain free carbonate, were used in this study. The results obtained by the proposed method were compared with those obtained by acid neutralization, calcimeter, and titrimetric methods. Analysis of variance revealed no significant difference between the percent CaCO 3 equivalent obtained by the four methods when the acid neutralization method was corrected against proton adsorption. However, the proposed method has the advantage of estimating Ca and Mg carbonates. The proposed method requires no special equipment and is less time-consuming if it follows the routine determination of exchangeable cations or the cation exchange capacity (CEC).
NOTES
1 Contribution from the Dep. of Biochemistry and Soil Science, Faculty of Agric., Univ. of Khartoum, Shambat, Sudan.
2 Associate Professor and Lecturers, respectively. Corresponding author, H.M. Abdel Magid, is now at the Dep. of Soil and Water, College of Agriculture & Vet. Med., King Saud Univ. Branch, Buraidah, Gassim, P.O. Box 1482, Saudi Arabia.
Received for publication January 13, 1987.