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Surface chemical properties and pedogenesis of tropical soils derived from basalts with different ages in Hainan,China 总被引：1，自引：0，他引：1
Limited information is available on the changes of surface chemical properties of tropical soils with time during the pedogenesis. Soil samples of three profiles derived from basalts of 10, 1330 and 2290 kilo annum (ka) in age were collected from adjacent locations in a tropical region of Hainan Province, China. The changes in soil surface chemical properties and the mineralogy of the soil clay fraction with time were investigated using ion adsorption, micro-electrophoresis, and X-ray diffraction analysis. The content of 2:1-type clay minerals decreased, while those of kaolinite and gibbsite increased with increasing basalt age and degree of soil development. The content of pedogenic free iron (Fe) oxides and the ratio of free Fe oxides/total Fe oxides increased with soil development stage, while soil poorly crystalline Fe and aluminum (Al) oxides had an opposite trend. The positive surface charge of the soils increased with increasing basalt age and degree of soil development; this was consistent with the change in their contents of free Fe/Al oxides. However, the value of negative surface charge had an opposite behavior. The soil derived from 10-ka-basalt had much more negative charge than soils derived from 1330- and 2290-ka-basalt. Soil net surface charge and zeta potential of the soil clay-fraction decreased with the increase in basalt age. Both net charge–pH curves and zeta potential–pH curves shifted to positive values with increased basalt age and degree of soil development. Increasing age also elevated the point of zero net charge of the soil and the isoelectric point of soil colloids. 相似文献
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在比较几种测定土壤电荷零点方法的基础上,研究了中南地区几种土壤的正负电荷量、电荷零点（ＰＺＧ）和净电荷零点（ＰＺＮＣ）。（１）推荐将盐滴定－电位滴 作为测定土壤ＰＺＣ的常规方法,该法较电位测定（ＰＴ）法简便、消耗样品量较少,而比盐滴定（ＳＴ）法获取的信息量较多。（２）铁铝氧化物是土壤正电荷的主要载体,其中非晶形铁铝氧化物具有重要贡献。（３）在低ＰＨ时土壤主要带永久负电荷随ＰＨ升高,土壤可变负电荷量 相似文献
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