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The International Union of Soil Sciences (IUSS) is the global union of soil scientists. The objectives of the IUSS are to promote all branches of soil science, and to support all soil scientists across the world in the pursuit of their activities. This website provides information for IUSS members and those interested in soil science.

WRB-Excursion on Technosols and Stagnosols

Germany in August 2007

The soil groups Technosols and Stagnosols which were introduced very recently into the WRB (world reference base on soil resources) have been studied during an eight days lasting excursion throughout Germany. This excursion started in the Ruhr area in North-West-Germany, on-going in the area of Halle and South of Halle in Central Germany, finally forwarding to South-West Germany. Proposals for the improvement of the WRB taxonomy were formulated during the in-door discussion at Hohenheim University at the last day. Twenty-eight participants from twelve countries shared the excursion which traced back to a proposition from A. Lehmann (Hohenheim) during the IUSS conference in Philadelphia in 2006. Hence, he took over the general organization of the tour. The WRB working group of the IUSS (O. Spaargaren/ Wageningen und P. Schad/ Weihenstephan) was invited by the AK Bodensystematik (Working group on soil systematic of the German Soil Science Society, G. Milbert/ Krefeld).

In total 35 main and some additional soil profiles were shown, 26 anthropogenic soils and 9 formed by stagnant water from natural rocks. The time spent on anhtropogenic soils and the time spent on the hydromorphic soils was nearly the same. This, because of longer distances to travel between the different soils with stagnant water.

The first part of the excursion took place at the starting point of the industrialization in Germany. This was in the anthropogenic strongly influenced Ruhr area.

The Technosols shown there were developed from transported soil material with addition of rubble, ashes, slags and mine spoil. These soils differed substantially in points of their functionality, in regard to the amount of in situ accumulated organic carbon, of decalcification, of alteration by stagnant water and in the occurrence of pedogenic formed minerals.

The natural soils influenced by stagnant water shown in the Ruhr area (annual precipitation: 820 to 930 mm, mean annual temperature: 9.6-C) were from unconsolidated sedimentary rock. Either from marine clay covered with fluvial sand and gravel or from Loess. An intense discussion about the interfering definitions of Stagnosols and Albeluvisols arose at the profiles.

In the evening of the second day, the excursion moved by train from the Ruhr area to Halle in Central Germany. There, the tour continued in the following morning. After a sound introduction into the area of Saxony-Anhalt, the excursion focuses on anthropogenic soils. Here, mainly soils developed from lignite ashes and other residues (oil residues and lime) of industrial processing have been discussed. Some discussions focused on the similarity and differences between Technosols from ashes and Andosols as well as of the current definition of artefacts.

The part of the tour in Central Germany was closed by the presentation of a natural soil in the Wermersdorfer forest (annual precipitation: 650 mm, mean annual temperature: 8,4-C) influenced by stagnant water. There, Gustaf Adolf Kraus (1888-1968) developed the concept of “gleiartige Boden” which leads to the soil type Pseudogley in the German soil classification. Again, the overlap between Stagnosols and Albeluvisols was discussed at this site.

In the afternoon of the fourth tour-day, the group moved to Stuttgart and arrived there at late night. The following day and the morning of the last tour day was dedicated to a wide range of natural soils formed by stagnant water which were located on the Swabian Alb, in Upper Swabia and in the “Obere Glue”. Most of the presented hydromorphic soils were developed under 7-8 C mean annual temperature and 800-900 mm total annual rainfall. Only the hydromorphic soils presented on the following day in Stuttgart experienced 9 to 10-C annual temperature and 700 mm total annual rainfall.

At the last tour day again anthropogenic soils have been the main topic in the city area of Stuttgart. First, a dump site was visited. There, a Garbic Technosol heavily influenced by reductic gases, was developed. Starting from this 25 years old Technosol, three older anthropogenic urban soils have been shown. The oldest Technosol (from wastes and undisturbed for 85 years) showed intense in situ darkening.

WRB Working Group excursion on Technosols and Stagnosols 2007 in the

Participants of the AK Bodensystematik

The following day was up to constructive discussion for completions and changes of the WRB-framework. The Techno-/ Stagnosols-Tour was also the 25th jubilee of the WRB working group, which was initiated from FAO in 1980 as a follow up of the “Soil Map of the World” project and established in 1982 from the ISSS. We all were glad to have the WRB-veterans R. Dudal und H.P. Blume with us on the Techno/ Stagnosols-Tour. This, in order to benefit from their long-term memory. Finally, we want to thank the numerous here not namely mentioned contributors for their support during the preparation and running of the excursion. Also, we want to thank the generous sponsors, notably the DFG (German Research Foundation), the Universitatsbund Hohenheim, the Farny- and the Eiselen foundation, the DBG (German Soil Science Society) und the IUSS.

An update of the 200 pages comprising excursion guide is scheduled for December 2007:

A. Lehmann, R. Jahn, , G. Milbert, K. Stahr, W. Burghardt, P. Schad