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 (PZC)和净电荷零点 (PZNC)。 ( 1 )推荐将盐滴定 电位滴定 (STPT)法作为测定土壤PZC的常规方法 ,该法较电位滴定 (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 ,土壤可变负电荷量增加 ;δp(pH =PZC时的电荷量 )、CECK(pH =4 .0时K+ 吸附量 )和ECEC在一定程度上均可反映土壤的永久负电荷量 ;永久负电荷在一定程度上可被铁铝氧化物所掩蔽。 ( 4)铁铝氧化物是影响土壤PZC和PZNC的主要因子 ,土壤经DCB处理后 ,其PZC和PZNC显著降低 ,甚至消失 Based on the comparison of several methods for determining the zero charge of soil, the positive and negative charges, PZC and PZNC of several soils in central-southern China were studied. (1) It is recommended to use the salt titration potentiometric titration (STPT) method as a conventional method for the determination of soil PZC. The method is simpler than potentiometric titration (PT) and consumes less sample. However, the information obtained by the ST method More. (2) Fe-Al oxides are the main carriers of soil positive charge, among them amorphous Fe-Al oxides have important contribution. (3) The soil had a permanent negative charge at low pH, and the soil variable negative charge increased with the increase of pH; δp (pH = charge at PZC), CECK (K + adsorption at pH = 4.0) And ECEC reflect, to a certain extent, the permanent negative charge of the soil; the permanent negative charge is to some extent masked by the ferro-aluminum oxide. (4) Fe-Al oxides are the main factors affecting PZC and PZNC in soil. After treated by DCB, the soil PZC and PZNC significantly decreased or even disappeared