The acid neutralization method and manometric procedures, using several acid-reducing agent combinations, were compared to determine their suitability for carbonate determination in organic soils. The soil–acid reaction observed with the acid neutralization procedure was significantly influenced by the acid concentration and soil type. Mean soil–acid reactions were 0.394 and 0.412 meq/g with the 0.3 and 0.6 M HCl, respectively. Moreover, it ranged from 0.023 to 0.694 meq/g soil for different soil types. The comparison of manometric procedures that were made used different acid-reducing agent combinations of HCl, CCl3COOH, HClO4, and SnCl2, and FeCl2. Of these, the HClO4–SnCl2 combination gave the lowest mean blank reading and standard deviation that remained stable (0.05 ± 0.009 ml). Though the perchloric acid alone is adequate for calcitic determinations, using the SnCl2 reducing agent with longer reaction times is recommended.