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| Titel |
Effect of experimental summer drought on greenhouse gas fluxes from soil under corn and sorghum |
| VerfasserIn |
M. Deppe, R. Manderscheid, R. Well, H.-J. Weigel, H. Flessa |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250065255
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| Zusammenfassung |
| For most of Central Europe climate change is supposed to lead to higher frequencies of
extreme weather events with hotter and drier summers. These changing climate conditions
will affect vegetation and the water cycle. Water content is one of the most important
parameters controlling production rates and fluxes of the greenhouse gases nitrous oxide
(N2O) and methane (CH4) from soil. Drought periods directly affect water content in soil and
thereby turnover rates of nitrogen and carbon; however, type and mass of plant coverage can
modify the degree of desiccation.
We conducted measurements of greenhouse gas emissions (N2O, CH4 and CO2)
and nitrogen dynamics (nitrate and ammonium) on an experimental field site on
loamy sand soil in Northern Germany. The site was installed to study the effect of
summer drought on biomass production of sorghum compared to corn. During
summer, plants on ’wet’ plots were irrigated whereas on ’dry’ plots rain was excluded
by transparent rain shelters to obtain less than 40% of plant available soil water
content.
Measurements were performed weekly over 1 1
2 years, including two periods of experimental
drought. Soil water content and nitrogen dynamics were measured from soil samples
and fluxes of N2O, CH4 and CO2 were measured between plant rows using static
chambers.
First results of greenhouse gas fluxes show increased uptake of methane in soil of ’dry’
compared to ’wet’ plots. No clear impact on N2O emission could be identified until now,
although N dynamics differed. Although corn growth was reduced to a greater extent than
was sorghum growth under drought conditions, biomass production of corn was higher under
both water regimes. Desiccation was higher and started earlier at ’dry corn’ than at ’dry
sorghum’ plots in summer 2011, leading to lower CO2 emission and higher CH4 uptake in
the drier soil. |
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