National Natural Science Foundation of China (No. 41877007)
塿土是关中地区受人为长期土粪堆垫而在原土壤表层形成明显堆垫层的重要农业土壤，其分类一直备受关注。为了解塿土的成土特点及系统分类归属，选取关中地区18个典型塿土剖面，通过野外成土因素、剖面形态调查与土样分析测定，依据中国土壤系统分类方案，确定其在高级和基层分类单元归属。结果表明，供试剖面包含堆垫表层、黏化层、钙积层等9个诊断层和诊断特性，隶属5个亚类，其中3个剖面为钙积土垫旱耕人为土，2个剖面为斑纹土垫旱耕人为土，8个剖面为普通土垫旱耕人为土，4个剖面为堆垫简育干润淋溶土，1个剖面为普通简育干润雏形土；按土族划分标准，可分为9个土族，其中13个剖面颗粒大小级别为黏壤质，5个为壤质；16个剖面矿物学类型为硅质混合型，2个剖面为混合型，土壤温度状况均为温性，14个剖面为石灰性，4个剖面为非酸性；按土系划分标准，18个剖面可划分为18个不同的土系。相关文献的71个塿土剖面的统计结果表明，堆垫层厚度介于17～97 cm，平均厚度为50.07 cm，因此堆垫表层以50 cm厚度为检索标准是适宜于划分典型塿土的高级分类归属的。为进一步完善中国土壤系统分类，强化对具有堆垫现象的雏形土有更强的区分能力和分类的准确性，建议在简育干润雏形土土类下增设堆垫简育干润雏形土亚类。
[Objective] Lou soil is an important agricultural soil that has an apparent cumulic epipedon formed on the top as a result of long-term dung stacking therein in the Guanzhong Region of Shaanxi Province, and its classification has received much attention. In order to explore its pedogenic characteristics and attribution in the soil taxonomy and to establish a perfect representative soil system, a total of 18 typical Lou soil profiles were selected in the region.[Method] Of the 18 soil profiles, natural soil forming factors and morphologies were studied and in reference to the Manual of Field Soil Description and Sampling, soil samples collected for analysis of physicochemical properties in reference to the Soil Survey Laboratory Methods. On such a basis, diagnostic horizons and diagnostic characteristics of the selected soil profiles were determined, and their attributions in the Chinese Soil Taxonomy (CST) at the higher and basic category levels defined.[Result] The selected Lou soil profiles were found to have 2 diagnostic surface horizons (cumulic epipedon, ochric epipedon), 3 diagnostic subsurface horizons (argic horizon, calcic horizon and cambic horizon) and 6 diagnostic characteristics (calcaric property, redox features, mesic soil temperature regimes, ustic soil moisture regimes, cumulic evidence and calcic evidence). Thickness of the cumulic epipedon was the key indicator for determining attribution of the Lou soil at the order level. Of the 18 profiles, 13 were sorted into orthic anthrosols with a corresponding cumulic epipedon diagnostic horizon, 4 into ustic argosols, and 1 into ustic cambosols with a corresponding 20~50cm thick cumulic epipedon. They were attributed to 3 subgroups (Calcic Earth-cumuli-Orthic Anthrosols, Mottlic Earth-cumuli-Orthic Anthrosols and typic Earth-cumuli-Orthic Anthrosols) under Group Orthic Anthrosols, one to Subgroup Cumulic Hapli-Ustic Argosols under Group Ustic Argosols and one to Subgroup Typic Hapli-Ustic Cambosols under Group Ustic Cambosols. According to the criteria for sorting at the soil family and soil series levels in CST, they could be sorting into nine soil families (clay loamy mixed type mesic temperature-Calcic Earth-cumuli-Orthic Anthrosols, etc.) and 18 soil series (Yangling series, etc.). Attributes of the Lou soil profiles in the CST and the Chinese Soil Genetic Classification (CSGC), did not always match, for example, three different soil series (Yangling series, Zhenyuan Series and Linping Series) in the CST corresponding to the same soil species (Red oil soil) in the CSGC. The statistics of 71 Lou soil profiles in relevant literatures shows that the cumulic epipedons in the Lou soils varied in range of 17-97 cm in thickness, and averaged to be 50.07 cm.[Conclusion] Compared with the Chinese Soil Genetic Classification, the Chinese Soil Taxonomy reflects and characterizes more accurately differences between the soils in soil development process and degree. The criterion of 50 cm thick cumulic epipedon is appropriate for classification of Lou at high levels soil. In order to improve the ability and accuracy of classification of prototype soils with cumulic phenomenon, it is suggested that the subgroup of Cumulic-Hapli-Ustic Cambosols under Group Hapli-Ustic Cambosols should be added in the CST.
吴娟,齐雁冰,常庆瑞,刘梦云,白丽敏.关中地区塿土系统分类归属及代表土系建立[J].土壤学报,2021,58(2):357-371. DOI:10.11766/trxb201906240325 WU Juan, QI Yanbing, CHANG Qingrui, LIU Mengyun, BAI Limin. Attribution of Lou Soil in Chinese Soil Taxonomy and Establishment of Representative Soil Series in Guanzhong Area[J]. Acta Pedologica Sinica,2021,58(2):357-371.复制