海南岛橡胶园土壤粘土矿物组成与土壤电荷量

Clay Mineralogy and the Amount of Charge of Rubber Plantation Soils in Hainan

对海南岛14个胶园土壤中粘土矿物组成及土壤表面电荷量进行了研究。结果表明:①供试胶园土壤粘土矿物以高岭石为主,部分土壤中还含有水云母、1.4nm矿物及三水铝石。各粘土矿物组分含量因气候生态区、发育母质及地形而异;②胶园土壤表面以负电荷为主,负电荷量随土壤pH值的升高而增加,表明其为可变负电荷;③橡胶园土壤正电荷量少,且随pH值升高而减少;④低pH值时,不同母质发育的土壤正电荷量大小顺序为:玄武岩﹥浅海沉积物﹥花岗岩和砂页岩。

Fourteen rubber plantation soils in Hainan Province were sampled to determine clay mineral constituents and soil surface charge. Kaolinite in the clay fraction was predominant in these soils tested, although hydromica, 1.4 nm intergrade minerals and gibbsite were included in some parts of the soils, and the contents of the clay minerals varied with climate, parent material and landform. Most of the rubber plantation soils had negative charge on the surface, and the negative charge increased with the pH value, indicating this negative charge is variable. The positive charge was very low in the rubber plantation soils, and decreased with the increase of pH value. At the low pH the positive charge of the rubber plantation soils derived from different parent materials increased in the order of basalt 〉 neritic sediment 〉 sand shale and granite.