GEMAS – Chemistry of Europe’s Agricultural soils, Single element maps, K - Potassium

GEMAS (Geochemical Mapping of Agricultural and Grazing Land Soil in Europe) is a cooperative project between the Geochemistry Expert Group of EuroGeoSurveys and Eurometeaux. In total, more than 60 international organisations and institutions worldwide were involved in the implementation of the project. During 2008 and 2009, a total of 2219 samples of agricultural (arable land soils, 0 – 20 cm, Ap samples) and 2127 samples of grazing land (pasture land soils, 0 – 10 cm, Gr samples) soil were collected at a density of 1 site/2 500 km² each from 33 European countries, covering an area of 5,600,000 km². All samples were analysed for 52 chemical elements after an aqua regia extraction, 41 by XRF (total), TC and TOC. In addition, the agricultural soil samples were analysed for 57 elements in a mobile metal ion (MMI®) extraction and Pb isotopes. All analytical results were subject to tight external quality control procedures. The GEMAS project thus provides for the first time fully harmonised data for element concentrations and bioavailability of the elements at the continental (European) scale. The downloadable files present the areal distribution of the element contents determined by different analytical methods in the shape of colour shaded contour maps with a classification in 7 and 72 levels each.