Plaggic Anthrosol: Soil of the Year 2013 in Germany An overview on its formation, distribution, classification, soil function and threats

The Plaggic Anthrosol (German: Plaggenesch) has been elected Soil of the Year 2013 in Germany. This article reviews present knowledge on the formation, distribution, classification, soil functions, and threats of Plaggic Anthrosols. As the colors of Plaggic Anthrosols differ, we introduce a Grey Plaggic Anthrosol and a Brown Plaggic Anthrosol. The term Plaggic Anthrosols is used in WRB, whereas those soils are classified as Agrosems according to the Russian, as Plagganthrepts according to the US Soil Taxonomy, and Plaggenesch according to the German taxonomy. The formation of Plaggic Anthrosols is the result of a former arable land use technique, the plaggen agriculture, starting approximate to 1000 y ago and lasting since the introduction of mineral fertilization. During processing plaggen agriculture, plaggen or sods of humic topsoil horizons were cut in the landscape, carried to the stables, enriched with dung, and subsequently spread out onto the fields as an organic-earthy manure. The manure decomposed and humified, whereas the mineral fraction remained and raised the land surface by 0.1cm y(-1) in average. Hence, the diagnostic horizon, a thick (70-130 cm) humus-rich man-made epipedon, often containing artefacts, was formed over time. The main region of spatial distribution of Plaggic Anthrosols is NW Germany, The Netherlands and NE Belgium. Minor occurrences are reported from other parts of Europe. Compared to the associated soils, Plaggic Anthrosols hold considerable natural, archive and utilization functions, but are threatened by degradation when their use as arable soil is rendered.