Institute of Soil Science, Agricultural College of Norway, Vollebekk, Norway
Soil samples from A0, A2, B and C horizons representing distinctly acidic profiles of humus podzol with raw humus, humus podzol with peat, iron humus podzol and iron podzol were studied for content of Mn. There was generally a high concentration of exchangeable Mn (maximum of 332 ppm) in A0 layer. Total Mn in humus samples (A0 horizon) for different podzols ranged from 0.005 to 0.5 per cent. B horizon contained, on the average, more exchangeable Mn than in lower layers, while HCl soluble Mn increased with depth from A2 to C horizon. In humus samples, a high percentage of total Mn constituted as exchangeable. These observations have been explained as a function of pH and conditions for reduction due to organic matter. Positive correlations were found between the amount of exchangeable Mn and the content of organic matter in all types of podzols.
