Umsatz verschiedener Ernterückstände in einem Bodensäulenversuchssystem - Einfluss auf die organische Bodensubstanz und den Transport zweier Xenobiotika.

Drewes, Norbert

Dissertation / PhD Thesis/Book

Umsatz verschiedener Ernterückstände in einem Bodensäulenversuchssystem - Einfluss auf die organische Bodensubstanz und den Transport zweier Xenobiotika.

Drewes, N. (Corresponding author)FZJ*

2005
Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag Jülich
ISBN: 3-89336-417-X

Jülich : Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag, Schriften des Forschungszentrums Jülich. Reihe Umwelt / Environment 59, XI, 201 S. (2005) = RWTH Aachen, Diss., 2005

Please use a persistent id in citations: http://hdl.handle.net/2128/492

Abstract: Knowledge about the formation and structure of soil organic matter provides essential contributions towards understanding fundamental soil functions and thus contributes to securing a high-yielding and sustainable agriculture. With a view to the translocation or immobilization and the conversion of widely differing xenobiotics, soil organic matter has frequently received attention in numerous studies. In the present study, the conversion of four different crop residues (maize straw, sugar beet leaves freeze-dried, oat straw, rape straw), applied in quantities as usual in agricultural practice, and their impact on the transport behaviour of the two xenobiotics benzo[a]pyrene and benazolin was investigated in soil column experiments with undisturbed soil cores (40 cm length, 20 cm diameter) of an orthic luvisol. In addition, a soil column variant without crop residues was examined for comparison. During the experimental period, different physical and chemical parameters were observed in the soil of the soil cores and in the percolate. Particular attention was given here to the structure of the soil organic matter, which was investigated by different spectroscopic methods. The results of the study can be summarized as follows: • The conversion of the different crop residues was observed for twelve weeks by measuring soil respiration rates. Subsequently, selected soil columns were segmented and the elemental composition of the soil segments analysed. During the experimental period, the pH value and the DOC content in the percolate were determined. By recording the soil respiration rates it was possible to reproduce both the quality of the crop residues and the conversion profile. Thus, for example, the freeze-dried beet leaves with soil respiration rates of 10 g ⋅ m$^{–1}$ h$^{-1}$ were converted much faster than the other crop residues. The influence of soil tillage operations prior to incorporating the crop residues on the activity of soil microorganisms was also documented. This technique newly introduced at the institute has proved very efficient and can be a valuable aid in further noninvasive studies of microbial activity. Sampling times can also be better defined by accompanying measurements. • The discharge of dissolved organic carbon was observed for twelve weeks after incorporating the crop residues. The DOC concentrations in the percolate of the soil columns varied significantly both within one variant and between the soil columns. DOC concentrations between approx. 30 mg ⋅ L$^{-1}$ and more than 2500 mg ⋅ L$^{-1}$ were measured in the percolate. For the extremely high DOC concentrations no parallel was found for other experimental arrangements in the literature. Nevertheless, the critical micelle concentration was not attained. The incorporation of the crop residues led to an increase in DOC concentration in nearly all the soil columns and then decreased [...]

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