“带有可变电荷的土壤”,简称“可变电荷土壤,”这一名词不仅在我国甚为生疏,在国外也并不为大家熟知。今年二月间,国际土壤学会在新西兰召开了一次有三十多个国家约三百余名土壤学者参加的“可变电荷土壤”国际会议。这标志着土壤学研究进展的一个新阶段。本文结合会议的情况,谈几个有关问题。 一 土壤的“可变电荷”是相对于“永久电荷”而言的。土壤带有电荷,这是土壤区别于纯砂,因而具有肥力的基本原因。这种带电现象也是土壤学中早已知道的。土壤的“阳离子交换量”,早已成为区分土壤类型的一个重要指标。 使用这一指标的基本出发点,是认为某一土壤带有一定数量的负电荷,因而吸附等当量的阳离子。由于一种土壤的负电荷数量为该土壤所固有,不随环境条件而变,所以这个阳离子吸附(交换)量也是一个恒值。虽然早已知道,这个“阳 “Soil with variable charge”, referred to as “variable charge soil,” is a term that is not only very rusty in our country but also not well known in foreign countries. In February this year, the International Society of Soil Science held an international conference on “Variable Charge Soils” involving about 300 soil scientists from over 30 countries in New Zealand. This marks a new phase in the progress of soil science research. This article combines the situation of the meeting, to talk about a few related issues. A soil “variable charge” is relative to the “permanent charge” in terms of. The soil is charged, which is the basic reason why soils differ from pure sand and therefore have fertility. This phenomenon of electrification is also already known in pedology. Soil “cation exchange capacity”, has long been the distinction between soil types an important indicator. The basic starting point for using this indicator is to think of a certain soil with a certain amount of negative charge, thus adsorbing an equivalent amount of cations. Since the amount of negative charge of a soil is inherent to the soil and does not vary with environmental conditions, the amount of cation adsorption (exchange) is also a constant. Although I already knew that this "yang