Two variable charge soils were submerged after the addition of 30g/kg of organic matter to examine the differences in behavior between iron and manganese with respect to reduction and the distribution of different for...Two variable charge soils were submerged after the addition of 30g/kg of organic matter to examine the differences in behavior between iron and manganese with respect to reduction and the distribution of different forms of the reduced elements. The reduction of manganese proceeded almost synchronously with the fall in redox potential, while the reduction of iron showed a remarkable lag behind the Eh change. Once formed,the distribution of water-soluble, exchangeable and precipitated forms of ferrous iron was controlled by PH,CEC of the soil and total concentration of the element. For manganous ions, the proportions of water-soluble and exchangeable forms in total Mn(2+) were larger than those for ferrous ions. The reduction of the two elements led to a mobilization of them, and such effect persisted even after drying of the soil, i.e.,the content of amorphous Fe became higher than that of the original soil.展开更多
文摘Two variable charge soils were submerged after the addition of 30g/kg of organic matter to examine the differences in behavior between iron and manganese with respect to reduction and the distribution of different forms of the reduced elements. The reduction of manganese proceeded almost synchronously with the fall in redox potential, while the reduction of iron showed a remarkable lag behind the Eh change. Once formed,the distribution of water-soluble, exchangeable and precipitated forms of ferrous iron was controlled by PH,CEC of the soil and total concentration of the element. For manganous ions, the proportions of water-soluble and exchangeable forms in total Mn(2+) were larger than those for ferrous ions. The reduction of the two elements led to a mobilization of them, and such effect persisted even after drying of the soil, i.e.,the content of amorphous Fe became higher than that of the original soil.
