Partner und Internationale Organisationen
(Englisch)
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Institute for Biogeography, Saarland University (D); JCR, lspra (1); National Agricultural Research Foundation, Athens (EL)
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Abstract
(Englisch)
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Unlike for chemical soil analyses, quality management procedures are hardly developed for the pre-steps of soil sampling and sample preparation. The objective of the project was to compare and to test the soil sampling and sample preparation guidelines used in the member states of the EU and Switzerland for inorganic soil contaminants (Cd, Cu, Pb, Zn) on a test area (Dornach, Switzerland) as a bases for the developement of adequat standard operating procedures (SOP). The Swiss contributions were mainly the selection and description of a suitable test area, the reference grid sampling and the organisation of the soil sampling proficiency test in the field. Altogether seven sites were investigated. A detailed soil survey of the finally selected test area (0.61 ha) at Dornach near Basel revealed four distinct soil land units. The main sources of heavy metals are (1) of geogenic origin, especially for Cd, (2) airborne pollution by emissions of a non-ferrous metal recycling plant e.g. Cu, Zn, Pb, Cd, (3) Cu-treatment of orchard trees, (4) contaminated fertilizers and (5) deposits of urban topsoil. The reference sampling followed four devices: (1) composite samples (0-10 cm and 0-20 cm), each from 25 stratified single samples from 61 squares of 10 by 10 m, (2) hypotheses and soil horizon based composite samples at nine locations, (3) horizon related samples from the four described soil profiles representing the mapping units, and (4) three soil cores with 5 cm interval samples taken in the major land use units. Altogether 301 reference soil samples were taken. The 15 participants from 14 countries were allowed to take at maximum 15 samples (single or composite) each to investigate the test area. The samples were prepared and analysed by the participants themselves and a representative portion of all samples was sent to the reference laboratory for chemical analyses. The results were compared to the reference data base. The results demonstrate, that the deviation due to sampling and sample preparation is of the same magnitude than the one for chemical analyses. With regard to sampling, the main elements to improve comparable results are to harmonise sampling depth and surface stratification. The results of the project are an important bases for the total revision of the guideline for soil sampling and sample preparation within the frame of the Swiss Ordinance to Impacts on the Soil.
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