广西岩溶地区水稻土发生特性及其在中国土壤系统分类中的归属

为明确广西岩溶地区水稻土在中国土壤系统分类中的归属，以该区域不同母质发育的水稻土为研究对象，挖掘20个典型剖面，通过野外观测、分层取样与分析，依据《中国土壤系统分类检索（第三版）》进行分类检索。结果表明，大多剖面出现明显的复钙现象。供试剖面的系统分类高级单元归属为人为土土纲，水耕人为土亚纲，潜育、铁聚和简育水耕人为土3个土类，复钙、铁聚和普通潜育水耕人为土、复钙和普通铁聚水耕人为土、复钙和普通简育.水耕人为土7个亚类，在系统分类基层单元归属上，可划归出17个土族和续分为20个土系。考虑广西地区水耕人为土耕作层Ap1碳酸钙相当物含量往往低于犁底层Ap2的现象，而现行水耕人为土复钙亚类的检索中“表层土壤”的“表层”不尽明确而可能导致的亚类误判，建议将其修改为“水耕表层（耕作层或犁底层）土壤”；另外，由于实际调查发现广西地区的一些铁聚水耕人为土也具有复钙特征，建议在检索中增设复钙铁聚水耕人为土亚类。

Genetic Characteristics of Paddy Soils in Karst Areas of Guangxi and Their Attribution in Chinese Soil Taxonomy

To clarify the classification of paddy soils in Karst areas of Guangxi in Chinese Soil Taxonomy, 20 typical soil profiles of paddy soil with different parent materials were selected and classified according to Chinese Soil Taxonomy (3rd ed) by field observation, stratified sampling and analysis. Results show that there is obvious recalcification in most of the paddy soils. The selected profiles are sorted into Anthrosols in Order, Stagnic Anthrosols in Suborder; Gleyic, Fe-accumulic and Hapli-Stagnic Anthrosol in Group, Recalcatic, Fe-accumulic and Typic Gleyi-Stagnic Anthrosols, Recalcatic and Typic Fe-accumulic-Stagnic Anthrosols, Recalcatic and Typic Hapli-Stagnic Anthrosols in Subgroup. They are classified as 17 soil families and 20 soil series. In consideration of that the CaCO3 equivalent content is lower in the cultivated layer of Stagnic Anthrosols in Guangxi than that in the plow pan, it is suggested to revise "the surface layer" of "topsoil" in the current classification of subgroup of Stagnic Anthrosols as Anthrostagnic epipedon (cultivated layer or plow pan) to prevent the misjudgment of subgroup. ". Meanwhile, it is suggested to add a subgroup of Recalcatic Fe-accumulic-Stagnic Anthrosols in Chinese Soil Taxonomy due to some of the artificial soils in Guangxi also have the characteristics of calcic evidence.