滇桂地区变性土的发生特性和系统分类研究

本文研究了我国西南地区变性土的形成条件和发育程度，并结合世界主要分类系统进行了分类研究。结果表明，相对于地带性土壤而言，变性土风化成土作用较弱，发育程度较低，土壤中元素的淋溶迁移及相对富集程度也远低于地带性土壤。由于粘粒含量尤其是粘粒矿物组成的差异，变性土表现出极高的膨胀潜势。通过研究，本文还对我国土壤系统分类中变性土土钢、亚纲、土类等的划分标准和依据及变性土性土的确立等提出了见解。

GENESIS AND TAXONOMIC CLASSIFICATION OF VERTISOLS IN YUNNAN-GUANGXI REGION OF CHINA

For the understanding of the distribution of Vertisols and vertic soils in Yunnan-Guangxi region of China and better use of the soils, seven profiles were collected for the study of genetic properties and taxonomic classification. The results showed that the weathering process of Vertisols was much weaker than that of zonal soils. The element hyper-geochemical features also showed the same regularity because of the lower degrees of relative enrichment of Al, Fe and Mn and leaching of K,Mg, Ca and Na in Vertisols. On account of the montmorillonites being over 35% of the clay minerals and a special microstructure, Vertisols had a very high swell-shrink potential with the swell-shrink value and COLE being 40% and 0.09 respectively. Meanwhile, high swell-shrink potential leads to the formation of unique micromorphology features, such as voids being mainly fissures, hairline cracks and plasma separations including asepic, insepic, masepic, lattisepic, vosepic and skelsepic. The results obtained showed that profiles belong to Vertisols, Ferrasols and Anthropic Soils, respectively, according to the Chinese Soil Tixonomic Classification, and some profiles of the latter two soil orders maybe fall into the vertic subgroup. Some delimiting standards of orders, suborders and great groups of Vertisol and vertic soils are suggested.