摘要
A study on the distribution of free iron and manganese oxides was conducted in soils developed on calcareous alluvial deposits under subhumid climatic conditions, in Western Greece. Soil samples from two well drained soils and from two poorly drained soils, classified as Alfisols, were collected and used in this study. After certification of soil homogeneity the acid ammonium oxalate and dithionite-citrate-bicarbonate methods were used to extract free iron and manganese oxides from the samples. Iron oxides extracted by the dithionite-citrate-bicarbonate method (Fed) were significantly higher than the iron oxides extracted by the ammonium oxalate method (Feo), indicating that a considerable fraction is present in crystalline forms,independent of drainage status. A confirmation of free iron oxides and fine clay was detected. The ratios Feo/Fed and (Fed-Feo)/total Fe (Fet) could not be used to distinguish the well drained soils from the poorly drained soils. Manganese movement in a soluble form is independent of the fine clay.
A study on the distribution of free iron and manganese oxides was conductedin soils developed on calcareous alluvial deposits under subhumid climatic conditions, in WesternGreece. Soil samples from two well drained soils and from two poorly drained soils, classified asAlfisols, were collected and used in this study. After certification of soil homogeneity the acidammonium oxalate and dithionite-citrate-bicarbonate methods were used to extract free iron andmanganese oxides from the samples. Iron oxides extracted by the dithionite-citrate-bicarbonatemethod (Fe_d) were significantly higher than the iron oxides extracted by the ammonium oxalatemethod (Fe_o), indicating that a considerable fraction is present in crystalline forms, independentofdrainage status. A confirmation of free iron oxides and fine clay was detected. The ratiosFe_o/Fe_d and (Fe_d-Fe_o)/total Fe (Fe_t) could not be used to distinguish the well drained soilsfrom the poorly drained soils. Manganese movement in a soluble form is independent of the fine clay.
关键词
氧化物
石灰质
冲积的
沉淀
淋溶土
氨
argillic horizon
calcareous alluvial deposits
iron oxides
manganeseoxides
soil homogeneity