Topsoil: Properties, Characteristics, and Proposed Soil Classification.

Topsoil: Properties, Characteristics, and Proposed Soil Classification

Topsoil is ambiguously defined, and is used commonly with terms such as “loam,” by non-soil scientists, which lends confusion in its use.  The purpose of this paper is to attempt to define topsoil and its properties, characteristics, and to propose a topsoil classification system.  The goal is to generate dialogue for the purpose of properly using the term topsoil and to understand how to manage this soil resource in the emerging areas of urban soils, urban gardening, raised beds, and permaculture, as well as in traditional agriculture.  A proper understanding of topsoil is also critical in the establishment of constructed wetlands and rain gardens used in stormwater management.  The proposed topsoil classification system may be useful in the communication to customers of retail and wholesale sellers of topsoil.  Physical, chemical, and biological properties will be presented as they are used in the proposed topsoil classification system.  Attributes and characteristics of topsoil such as bulk density, consistence, coarse fragments, color/organic matter, crusting, pH, roots, soil fertility, structure, and texture will be presented as they apply to the proposed topsoil classification system.  The proposed topsoil classification system will include value ranges of attributes, importance weighting of attributes, calculated values, and a rating.