Data and Concepts
The mapping of soils at a scale of 1:200,000 to produce a general soil map was initiated by the Geological Survey of Finland (GTK) in the early 2000s. The Soil Classification Database project was launched in 2003 in cooperation with MTT and Metla. Through this project, soil-type observation points from agricultural field parcels and soil data from the National Forest Inventory (NFI) were incorporated as reference material for the mapping process.
As part of the general soil survey, the topsoil type was also determined. A soil profile was defined as the layer located between the topsoil and subsoil. Soil profiles are generally stratified and consist of soil materials with different particle sizes as well as organic matter. In Finland, the most common soil profile type is the nutrient-poor podzol found in coniferous forests.
Version 1.0 of the Soil Classification Database was overlaid with the basic field parcels from the Ministry of Agriculture and Forestry Information Centre (Tike) field parcel register for 2011, and the resulting information was aggregated to the municipal level. The soil type of each field parcel was determined based on this overlay. This process produced datasets describing the soil types of agricultural land by municipality. The national soil classification was produced similarly from GTK's general soil map, which is a parallel product of the Soil Classification Database.
In the Soil Classification Database, soil types have been classified according to the international WRB2007 classification system (World Reference Base for Soil Resources). The database contains a total of 19 soil types, defined on the basis of both topsoil and subsoil characteristics.
According to the Finnish soil classification system, soil types have been determined separately for the topsoil and subsoil of each field parcel. The national classification contains a total of 16 soil-type classes. In the reports, the main soil-type categories are mineral soils and organic soils. These are further divided into subclasses and, subsequently, into individual soil types.
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