【摘要】 本文就第四纪红土所发育的三种不同地势和不同肥力的水稻士的微团聚体特性,进行初步研究,其结果可概括为如下两点: （1）三种水稻土中钠分散微团聚体（C₁）的含量都在10%以下。地势较低而肥力较高的乌泥田,交换性钙离子飽和度较高,而G₁组含量并未增加,反而降低。钠-机械分散的微团聚体（G₂）以黄土田中最低,水分散微团聚体则较高,（G₀+G₁）/G₂的比值是:黄土田>红土田>乌泥田。红土田中各组微团聚体的碳氮含量差异不大,而乌泥田中各组微团聚体的碳氮含量差异较为明显（G₀≈G₁<G₂）。三种水稻土的G₂组中铁和铝有显著的积累现象。（2）根据微团聚体中有机质的表观交换量来判断,红土田的微团聚体中有机质与矿质复合形式可能以等电沉淀或等电凝胶的形式为主,除去有机质以后,微团聚体的交换量可增加18—25%,乌泥田的微团聚体中有机矿质的复合可能有负电性凝胶的形式,去除有机质后微团聚体的交换量反而减低。红壤性水稻土各组微团聚体吸收磷酸的作用,可能与铁化物的水化程度有关。同属第四纪红土所发育的水稻土,因漬水情况和耕作施肥的不同,各组微团聚体特别是G₂组的特性差异很大,很难简单地用（G₀+G₁）/G₂来反映红壤性水稻土的肥力水平,更难在不同土类之间进行比较。更多还原

【Abstract】 Three groups of micro-aggregate, including water dispersed（Go）, sodium dispersed（G₁） and mechanical-sodium dispersed micro-aggregate（G₂）, were separated by the peptization method from three groups of paddy soil derived from Quarternary red clay. The total amounts of micro-aggregates are 54, 58, 60% based on air-dry soil and the ratio of G₀ + G₁ : G₂ are 0.45, 0.94, 1.46 respectively. The properties of micro-aggregates of these three paddy soils are briefly described as follows: 1. The contents of carbon and nitrogen in the three groups of micro-aggregates show a relationship of G₀=G₁<G₂ for the gley submerged paddy soil but indicate no apparent variation for temporary submerged paddy soil. The content of organic matter in the micro-aggregates is about 59% of total soil organic matter for temporary submerged paddy soil and only 37% for gley submerged paddy soil. 2. The exchange capacity of micro-aggregates for temporary submerged paddy soil increases 18—25%（or 2.1—2.8 m.e. per 100 g. sample） after removal of organic matter with hydrogen peroxide, but shows no distinct change after this treatment for gley submerged paddy soil. 3. The ratio of adsorbed phosphate to free iron oxide in micro-aggregates is 18.4—19.4 for temporary submerged paddy soil and 27.5—30.7 for gley submerged paddy soil. From the above results, it seems unadvisable to take the G₀ + G₁ : G₂ ratio as an index of soil fertility for different soil groups.更多还原