Topsoil is an important component of most landscape projects and to maintain standards the British Standards Institute produced and published BS 3882. The first version of the standard was introduced in 1965 and was intended to provide a simple description and classification of topsoil for use in landscape work. The first of its true revisions since 1965, the BS 3882 underwent updates in 1994 and 2007.
Released in June 2015, it specifies requirements for topsoils that are moved or traded. This standard is not intended (or appropriate) for the grading, classification or standardisation of topsoil or subsoil that remains in situ.
BS 3882:2015 describes the performance requirements for Multipurpose Topsoil and Specific Purpose Topsoil.
Mulitpurpose Topsoil is fit for the majority of needs. It is described as that which includes natural top-soil or manufactured topsoil. When handled and managed appropriately and placed over a permeable subsoil it is capable of supporting grass, trees, shrubs and herbaceous plants. This grade should be suitable for most planting situations.
In the multi-purpose topsoil category, the main changes in BS 3882: 2015 are:
• The upper limit for extractable potassium has been increased from 900mg/l to 1500mg/l
• The upper level for electrical conductivity has been increased from 2800uScm to 3300uScm and there is no requirement for an Exchangeable Sodium Percentage test.
Specific Purpose Topsoil
Specific Purpose Topsoil includes natural or manufactured top soil with characteristics appropriate for specialist planting situations. These are split into the following groups:
- Low fertility
- Low fertility acidic
- Low fertility calcareous
BS 3882 also gives guidance on sourcing, handling, storing, sampling and analysis. Furthermore, it outlines the requirements that are necessary to ensure compliance with the specifications within the standard. When specifying multipurpose or specialist purpose topsoil, suppliers, specifiers and users should take into account how the topsoil will be used at the site.
The aim of all this is to ensure that the particular topsoil properties are fit for the intended planting.
Significant changes in the BS 3882: 2015 specific purpose topsoil category reflects the latest guidance on low-fertility soils for species-rich, biodiverse habitats.
The standard has been revised to align with BS 8601:2013 – Specification for subsoil – and to reflect users’ experience of previous versions of the standard and growing industry knowledge.