Baltic soil survey: total concentrations of major and selected trace elements in arable soils from 10 countries around the Baltic Sea.

Agricultural soils were collected from 10 European countries over a 1,800,000 km2 area surrounding the Baltic Sea. The sampling density was 1 site/2500 km2. Two samples were taken at each site: topsoil 0-25 cm (ploughing layer, Ap-horizon) and subsoil (bottom samples, usually B- or C-horizon) at an approximate depth of 50-75 cm, well below the ploughed layer. The samples were analysed for total element concentrations of 41 elements by WD-XRF. Analytical results for both layers are quite comparable. Large differences between element concentrations and variations can be observed for most elements when the different countries are compared. The Nordic countries show considerably higher concentrations and variations for quite a number of elements [Al, Fe, (Mg, P), Ti, Ba, Sc, Sr, V] in their agricultural soils. This is an expression of geology, the relatively younger age of the soils here and of the climatic conditions (reduced weathering rates). Regional geochemical maps demonstrate that geology overwhelmingly dominates the total concentration of chemical elements as observed in the agricultural soils. The three (four) large tectonic units (Caledonian mountain chain, Fennoscandian Shield and the northern and southern eastern European Platform) composing this area are all reflected in the regional maps.