可变电荷土壤和恒电荷土壤与氢离子相互作用机理

研究了可变电荷土壤和恒电荷土壤与H相互作用的机理，并比较了它们之间的差别，研究结果表明，氢离子输入土壤后可以转化为表面正电荷，可溶性铝和可交换性酸，但是由于土壤的组成和性质不同，不同土壤中H＋三种去向的贡献不同。H＋转化为表面正电荷是由于土壤表面Fe-OH,Al-OH的质子化造成的，因此H＋转化为表面正电荷的能力与土壤中氧化铁的含量密切相关，从而可变电荷土壤中H＋转化为表面正电荷的贡献比恒电荷土壤中的大。H＋转化为可溶性铝的能力与土教育部 的矿物组成密切相关，随着H＋输入量的增加，土壤中可溶性铝的含量也增加。可变电荷土壤中可溶性铝增加的顺序为红壤＞赤红壤＞铁质砖红壤，在H＋的加入量小于15mmol/kg时，黄棕壤的可溶性铝介于红壤和赤红壤之间，当H＋的加入量大于约15mmol/kg时，黄棕壤的可溶性铝略小于赤红壤，棕壤的可溶性铝明显小于红壤和赤红壤，但比铁质砖红壤高，恒电荷土壤的可变性酸量明显大于可变电荷土壤，但从总的看来，H＋加入量的变化对可交换性酸量的影响不大。

The mechanism of interaction of constant and variable charge soils with H + ions

The mechanisms of interaction of variable charge soils and constant charge soils with hydrogen ions were investigated and evaluated. The results showed that the input of hydrogen ions into soils could transform into positive charges, soluble A1 and exchangeable acidity. However, the relative contributions of hydrogen ions to the three transformations above are different due to the discrepancies in components and properties of soils. The transformation into positive charges arises mainly from protonation of Fe－OH and Al－OH functional groups on the surface of soils. Therefore, the ability of this transformation is strongly dependent on the contents of Fe oxide, and consequently the transformation in variable charge soils is larger than that in constant charge soils. The ability of transformation into soluble Al is dependent on the constituents of clay minerals in soils. The increases in soluble Al in soil solutions with increasing inputs of hydrogen ions are of the order: Paleudult ＞ Kanhapludult ＞ Hapludox. When the amounts of added hydrogen ions are less than 15 mmol/L, the amounts of soluble A1 in yellow-brown soil is between Paleudult and Kanhapludult, whereas they are slightly less than in Kanhapludult when inputs are more than 15mmol/kg. The amounts of soluble Al in brown soil are remarkably lower than those in both Paleudult and Kanhapludult, but higher than in Hapludox. The exchangeable acidity in constant charge soils is pronouncedly larger than that in variable charge soils. The influence of inputs of hydrogen ions on exchangeable acidity, on the whole, is small.