Effect of weathering on distribution of organic acids in relation to free iron and aluminium oxides in loess soils of Germany
1987
Sattar, M.A.
Two soil profiles of loess, collected around Giessen of the Province Hessen in West Germany were investigated. The soil types were Chernozem. Parabrownearth of Rockenberg (Parabrownearth similar to Gray-brown were loess, containing carbonates and basaltic solifluction products. The fulvic acid and humic acid contents in the surface soil of Lanzenhain profile are remarkably high on account of waterlogged condition of the soil. The fulvic acid content of the investigated profiles is higher in the lower horizons. Generally the fulvic acid accumulation increases, but the humic acid decreases with the decrease in pH. Both fulvic acid and humic acid contents are usually higher in clay-enriched horizons. A common relationship exists in distribution between percentages of fulvic acid and free Al(2)O(3) contents. A similar relationship is, however, observed between percentage contents of humic acid and free Fe(2)O(3). It is probable that Al is chelated more easily with fulvic acid, while Fe is more easily chelated with humic acid.
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