Pedosphere 23(4): 445--454, 2013
ISSN 1002-0160/CN 32-1315/P
©2013 Soil Science Society of China
Published by Elsevier B.V. and Science Press
Distribution, morphology, and chemical composition of Fe-Mn nodules in Albeluvisols of the Carpathian Foothills, Poland |
W. SZYMA?SKI1 and M. SKIBA2 |
1Department of Pedology and Soil Geography, Institute of Geography and Spatial Management, Jagiellonian University, Gronostajowa St. 7, 30-387 Cracow (Poland)
2Department of Mineralogy, Petrology and Geochemistry, Institute of Geological Sciences, Jagiellonian University, Oleandry St. 2a, 30-063 Cracow (Poland) |
ABSTRACT |
Iron and manganese oxides are common components of soils. They frequently occur in nodules constituting important soil sorbents and play a crucial role in a number of chemical reactions in the soil environment. In addition, the oxides are very sensitive to environmental changes (moisture, pH, Eh) constituting important indicators of soil-forming processes and water movement in the landscape. The objectives of the study were: i) to examine the distribution and size of Fe-Mn nodules in Albeluvisols containing a fragipan horizon; ii) to determine the morphology and chemical composition of the nodules, and iii) to estimate the effect of the fragipan horizon on water movement within the soil profile. An investigation was carried out on five soil profiles containing a fragipan horizon and classified as Fragic Albeluvisols within the Carpathian Foothills in Poland. In the Albeluvisols studied, the maximum concentration of Fe-Mn nodules occurred in the horizon lying directly on the fragipan horizon. This suggests that the pan acts as a natural barrier restricting water infiltration and leads to the seasonal development of a perched water table promoting redox processes. The most common are coarse (1--0.5 mm) and medium (0.5--0.25 mm) irregular Fe-Mn nodules showing a gradual boundary and undifferentiated internal fabric. Eluvial horizons contained also larger amounts of round and dense nodules with a sharp boundary, suggesting frequent oxidation and reduction. The fragipan horizon contained mainly irregular and soft nodules, suggesting longer saturation with water during the year. Concentrations of trace elements (Cu, Zn) and P were higher within Fe-Mn nodules than in the surrounding soil materials, showing that iron and manganese oxides adsorbed and immobilised these elements. |
Key Words: fragipan horizon, iron oxides, manganese oxides, perched water table, redox processes |
Citation: SzymaŃski, W. and Skiba, M. 2013. Distribution, morphology, and chemical composition of Fe-Mn nodules in Albeluvisols of the Carpathian Foothills, Poland. Pedosphere. 23(4): 445-454. |
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