Soil is the outside layer of Earth. It is a made up of living organisms, gases, minerals, and organic matter. Knowing what elements are in the soil helps to work out where it came from and how it was made. The GEMAS (geochemical mapping of agricultural soils and grazing land of Europe) project provides harmonised geochemical data of arable land and land under permanent grass cover across Europe. Geological Surveys in 34 European countries collected soil samples. Soil samples were taken on arable land from ...