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Temporal and spatial variability of the CH 4 dynamics of landfill cover soils
Author(s) -
Giani Luise,
Bredenkamp Jan,
Eden Ingeborg
Publication year - 2002
Publication title -
journal of plant nutrition and soil science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.644
H-Index - 87
eISSN - 1522-2624
pISSN - 1436-8730
DOI - 10.1002/1522-2624(200204)165:2<205::aid-jpln205>3.0.co;2-t
Subject(s) - soil water , spatial variability , methane , aeration , environmental science , chemistry , greenhouse gas , soil science , soil cover , environmental chemistry , atmospheric sciences , ecology , geology , mathematics , statistics , organic chemistry , biology
Landfills are regarded as important sources of the atmospheric methane (CH 4 ), one of the major greenhouse gases. In this study we investigated the CH 4 dynamics of landfill cover soils in a long‐term field experiment. The CH 4 emission rates were low, mostly ranging from —100 to 100 μmol m —2 h —1 , with prevailing negative values. Higher values of up to 130,000 μmol m —2 h —1 , obtained concurrently, were due to mice burrows, connecting the reduced soil sections with the aerated ones. Thus, the appearance of spatial dissimilarity was the most important factor influencing temporal variability. Reducing the soil cover from 120 cm to at least 60 cm caused a tendency of increased CH 4 emission. The oxidation rates were also low and differed with low temporal variability from 1.0—11.9 nmol g —1 h —1 in 0—10 cm soil depth and 0—5.3 nmol g —1 h —1 in 40—50 cm, respectively. Highest rates were obtained at 25—30 % soil water content. A mapping of CH 4 concentrations over the whole landfill showed a large spatial variation with values of 3.1—343 nmol g —1 . Subsequent CH 4 emission rates were between —0.2 and 120,000 mmol m —2 d —1 and showed a positive correlation to the CH 4 concentrations (r = 0.993, P < 0.05). Thus, by a large scale mapping of CH 4 concentrations a low‐cost procedure is proposed to identify the hot spots of CH 4 release which should be treated with additional thick and well aerated cover soil materials.