Characteristics and classification of anthropogenic soils in the Osnabrück area, Germany

Soils in the area around Osnabrück/Northwest Germany have been strongly influenced by man. The classification of these soils based on the German and international classification systems is problematical. Eight representative soils, two Anthrosols (plaggic and hortic), four soils affected by the coal and steel industry and consisting of distinct monosubstrata (coal and ore mining heaps, slag heap, sludge area) as well as two deposits of heterogeneous waste components (reclaimed wet land, filled quarry) were investigated. The sites are assessed in relation to their contamination by heavy metals and PAH as well as suitability for plant growth. An attempt was made to classify the soils using the current classification of World Reference Base for Soil Resources (WRB), German Soil Science Society Classification, FAO and the USA. These systems enables a satisfactory classification of two Anthrosols compared with the other soils. In the US taxonomy, the pedogenesis of technological substrata was not considered. In the FAO taxonomy, it is not acceptable to term all soils as Urbic Anthrosols without any further differentiation. This differentiation was enabled in both the WRB and the German taxonomy. In the WRB taxonomy, however, only anthropic subunits of the Regosols are included. An improvement could be achieved by the introduction of comparable subunits of the Arenosols, Durisols, Gleysols, and Leptosols. In the German taxonomy (normally soil and substrata are classified separately), the induction of toxic subunits in the presence of high soil contamination influencing the edaphon would be helpful. Furthermore, soils hardened by silica should be classified as respective varieties.