Soil classification in the soil survey of England and Wales
Soil classification in the soil survey of England and Wales
复制标题
英格兰和威尔士土壤调查中的土壤分类
DOI：
--
复制
发表时间：
1973
期刊：
影响因子：
--
通讯作者：
B. W. Avery
中科院分区：
文献类型：
--
作者：
B. W. Avery
总结
简要回顾了英格兰和威尔士土壤分类的发展，并介绍了一个供今后使用的系统。被分类的东西是土壤剖面，类别是由相对永久的特征确定的，这些特征可以在实地观察或测量，或者通过与分析样品进行比较，在实地检查的范围内推断。剖面类别通过递进划分分为四个分类层次，分别称为主组、组、亚组和土系。
三个更高类别中的类别部分地由土壤物质的组成来确定，部分地由特定深度内是否存在特定的诊断层或最近冲积成因的证据来确定。土系的区别在于其他特征，主要是岩性，而不是在更高的类别中区分。大多数土类被认为是土系之上的主要类别，在其他欧洲系统、美国农业部系统（第七近似法及随后的修正案）或这两种系统中都是紧密相连的。与迄今为止使用的系统相比，主要的创新是使用特定的土壤特性来定义所有类别级别的类别，以及主要基于继承的岩性特征在组级别上进行分类。
土壤剖面分类为确定土壤图单元提供了统一的基础，土壤图单元被视为划定的土壤体的类别。当一个地图单元以剖面类别的名称来标识时，这意味着每个划定中的大部分土壤都符合该类别，而不符合的夹杂物属于一个或多个密切相关的类别，或者占据的面积比例微不足道。在剖面分类中，由土地属性识别的图元不区分，称为相。
Summary
The development of soil classification as a basis for soil mapping in England and Wales is briefly reviewed, and a system for future use is described. The things classified are soil profiles, and classes are defined by relatively permanent characteristics that can be observed or measured in the field, or inferred within limits from field examination by comparison with analysed samples. Profile classes are defined at four categorical levels by progressive division, and are termed major groups, groups, subgroups, and soil series respectively.
Classes in the three higher categories are defined partly by the composition of the soil material and partly by the presence or absence of particular diagnostic horizons, or evidence of recent alluvial origin, within specified depths. Soil series are distinguished by other characteristics, chiefly lithologic, not differentiating in higher categories. Most of the soil groups, regarded as the principal category above the soil series, are closely paralleled in other European systems, in the U.S.D.A. system (7th Approximation with subsequent amendments), or in both. Compared with the system used hitherto, the main innovations are the use of specific soil properties to define classes at all categorical levels, and the separation at group level of classes based primarily on inherited lithologic characteristics.
The soil-profile classification provides a uniform basis for identifying soil map units, considered as classes of delineated soil bodies. When a map unit is identified by the name of a profile class, it is implied that most of the soil in each delineation conforms to that class, and that unconforming inclusions belong to one or more closely related classes or occupy an insignificant proportionate area. Map units identified by land attributes not differentiating in the profile classification are termed phases.