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| Titel |
Post-harvest N2O emissions were not affected by various types of oilseed straw incorporated into soil |
| VerfasserIn |
Sarah Köbke, Mehmet Senbayram, Hannes Hegewald, Olaf Christen, Klaus Dittert |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250111580
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| Publikation (Nr.) |
 EGU/EGU2015-14861.pdf |
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| Zusammenfassung |
| Oilseed rape post-harvest N2O emissions are seen highly critical as so far they are considered
as one of the most crucial drawbacks in climate-saving bioenergy production systems. N2O
emissions may substantially counterbalance the intended savings in CO2 emissions.
Carbon-rich crop residues in conjunction with residual soil nitrate are seen as a key driver
since they may serve as energy source for denitrification and, they may alter soil-borne N2O
emissions. As oilseed rape straw is known to have high N/C ratio compared to other crop
residues, its soil incorporation may specifically trigger post-harvest N2O emissions.
Therefore, the aim of the present study was to determine post-harvest N2O emissions in soils
amended with various types of oilseed rape straw (with different N/C ratio) and barley straw
in field and incubation experiments. In the incubation experiment, oilseed rape
or 15N labelled barley straw were mixed with soil at a rate of 1.3 t DM ha-1 and
studied for 43 days. Treatments consisted of non-treated control soil (CK), 15N
labelled barley straw (BST), oilseed rape straw (RST), 15N labelled barley straw + N
(BST+N), or oilseed rape straw + N (RST+N). N fertilizer was applied to the soil
surface as ammonium-nitrate at a rate of 100 kg N ha-1 and soil moisture was
adjusted to 80% water-holding capacity. In the field experiment, during the vegetation
period 15N labelled fertilizer (15NH415NO3) was used to generate 15N labelled
oilseed rape straw (up to 5 at%). Here, the three fertilizer treatments consisted of 5
kg N ha-1 (RST-5), 150 kg N ha-1 (RST-150) and 180 kg N ha-1 (RST-180).
Post-harvest N2O emissions were determined during the period of August 2013 to
February 2014 by using static flux chambers. In the incubation trial, cumulative
N2O emissions were 5, 29, 40 g N2O-N ha-1 148 days-1 in non-fertilized control,
BST and RST treatments, respectively. Here, emissions were slightly higher in
RST than BST (p |
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