中南地区几种地带性土壤表面电荷特性与pH的关系

用改进的Schofield法、盐滴定法等方法研究测定了我国中南地区5种不同地带性土壤的表面电荷特性。结果表明：1)在同一pH条件下，土壤负电荷量由北向南呈递减趋势，正电荷量呈递增趋势，与供试土壤粘土矿物、铁铝氧化物组成及含量有关；2)砖红壤中负电荷以可变负电荷为主，棕红壤和红壤既有较大数量的可变负电荷，并含有一定数量的永久负电荷，黄褐土和黄棕壤负电荷量随pH的变化较小；3)供试土壤的PZC从北到南逐渐升高，砖红壤的PZNC为4．2，其它土壤在试验pH范围内不存在PZNC。

Relationship between Surface Charge Properties of Several Kinds of Zonal Soils in Central Southern China and pH

Surface charge properties of five soil samples from zonal soils in China were studied by the improved Schofield method and potential titration method. The results showed as that: (1) The amount of negative charge increased with the increasing of pH value, while that of the positive charge decreased. At the same pH value, the negative charge quantity of the examined soils tended to decrease from north to south, whereas the positive charge increased. (2) The latosol bore variable negative charge as predominant charge, and the brown red soil and red soil bore not only some variable negative charge, but also some permanent negative charge. The negative charge was not significantly pH-dependent in yellow cinnamon soil and yellow brown soil. (3) The magnitude of PZNC for the latosol is 4.2, but that for other soils was not detectable in the experimental pH range. The magnitude of PZC tended to increase from yellow cinnamon soil to latosol.