幕阜山垂直带土壤的粘粒氧化物组成

THE OXIDES CONSTITUENTS OF MUFU MOUNTAIN SOIL CLAYS

用化学选择溶提法，测定了幕阜山不同海拔高度土壤及剖面不同层次的粘粒中铁铝氧化物的含量。结果表明：①随着海拔升高，土壤粘粒中有机络合态及非晶形的铁、铝氧化物含量增高，与土壤中有机质的含量呈显著正相关。②同一剖面不同层次的土壤，随着有机质含量由上向下递减，粘粒中络合态铁铝氧化物的含量也逐渐降低。③随着海拔升高，铁铝氧化物除了非晶形的含量增高之外，晶态三水铝石含量也增高，表明粘粒中氧化铝有随海拔升高而富集的特点。根据以上结果，讨论了铁铝氧化物活化与成土条件的关系，提出了幕阜山土壤的富铝化特征，并建议将诊断层土壤粘粒的氧化铁活化度作为山地土壤系统分类的指标之一。

The Contents of iron and aluminum oxides in MUfu mountain soil clays were determined by selective dissolution technique.The results indicated :①The contents of iron and aluminum oxides extracted from soil clay fraction treated with ammonium oxalate or sodium pyrophosphate increase with the increment of altitude.The amount of oxides are positively correlated with that of organic matter;therefore the active degree of Fe and Al oxides in soil clay fraction rises with the increment of altitude.The factors which affect the active degree of Fe and A l oxides in soil clay fraction may include the content of organic matter, the amount of rainfall and temperature.②In the same soil profile, the amount of Feo, Alo, Fep and Alp reduces when soil horizon declines. It is also because the amount of organic matter decreases.③The amount of gibbsite, Al extracted with DCB, sodium citrate, ammonium oxalate, pyrophosphate solutions in examined samples increases with the increment of altitude, implying that there is allitization in Mufu mountain soils, which is different from that in horizontal 20nal soils.