【摘要】 用自动控制ｐＨ的装置定量研究了两种红壤类土壤胶体在三种中性盐溶液中的交换性碱和交换性酸的变化。发现在Ｎａ_２ＳＯ_４溶液中在ｐＨ低时出现交换性碱，ｐＨ高时出现交换性酸。砖红壤胶体的交换性碱比红壤胶体的大，并且在ｐＨ５．６附近还出现不受Ｎａ_２ＳＯ_４浓度影响的交换中性点。ＮａＣｌＯ_４和ＫＣｌＯ_４溶液中，在测定ｐＨ范围内只出现交换性酸，红壤胶体的数量比砖红壤胶体的大。同一土壤胶体在ＫＣｌＯ_４中的数量比ＮａＣｌＯ_４中的多。二者都有一峰值，对于砖红壤胶体前者在ｐＨ４．３，后者在ｐＨ５．８。提出了测定ＳＯ４２－－交换性碱的方法。更多还原

【Abstract】 The changes of exchange alkalinity and exchange acidity in the two types of red soil with the Presence of three neutral salt solutions was studied quantitatively by pH controlled automatically equipment. It was found that in the solution of Na2SO4 the exchange alkalinity appeared at low pH, while exchange acidity at high pH .The amount of exchange alkalinity of latosol is larger than that of red soil. The exchange neutrality point which was not influenced by the concentration of Na2SO4 was nearby pH4.6. Only the exchange acidity appeared in the solutions of NaClO4. and KClO4 in the range of pH measured. The amount of exchange acidity was found more in the red soil than that in the latosol. For the same soil colloid the amount of exchange acidity in KClO4 solution was greater than that in the NaClO4 solution. The peak value of exchange acidity was shown at pH 4.3 in the solution of KClO4 and at pH 5.8 in the solution of NaClO4 for the latosol colloid. A method of measuring the SO42--exchange alkalinity was constructed.更多还原