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| Titel |
Contribution of nitrous oxide and methan to the overall climate impact of maize on well-drained sandy soils of north-east Germany |
| VerfasserIn |
M. Andres, U. Hagemann, M. Pohl, M. Sommer, J. Augustin |
| 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 |
250067271
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| Zusammenfassung |
| Erosion effects and the influence of organic fertiliser (fermentation residues, FR) on the
climate impact and greenhouse gas (GHG) emissions of N2O, CH4 and CO2 were
investigated at an experimental field side in the lowlands of north-east Germany during the
years 2010 and 2011. This intensively used agricultural landscape is glacially shaped and
characterized by well-drained sandy and loamy soils.
Erosion effects on GHG exchange were investigated for energy maize at the
CarboZALF-D project site near Dedelow, Uckermark. In addition to a non-eroded haplic
luvisol (reference), emissions were measured for three eroded soil types: a) eroded haplic
luvisol, b) haplic regosol (calcaric) and c) endogleyic colluvic regosol (deposition side). In a
second field trial, the impact of organic fertilization on GHG emissions was assessed for a
range of FR fertilization (0-200% N) and compared to a non-fertilized and a minerally
fertilized control. Only 70% of the N content of the FR was assumed to be available for
plants.
Discontinuous measurements of N2O and CH4 were carried out bi-weekly using the
closed-chamber method and 20-minute interval sampling. Gas samples were analysed using a
gas chromatograph. Gas fluxes were calculated using linear regression, interpolated and
finally cumulated. CO2 flux measurements of ecosystem respiration (Reco) and net ecosystem
exchange (NEE) were conducted every four weeks by using a non-flow-through
non-steady-state closed chamber system (Livingston and Hutchinson 1995) based on Drösler
(2005). Measurement gaps of NEE were filled by modeling the Reco fluxes using the
Lloyd-Taylor (Lloyd and Taylor 1994) method and the gross primary production (GPP)
fluxes using Michaelis-Menten (Michaelis and Menten 1913) modeling approach.
Annual NEE balances were then calculated based on the modeled Reco and GPP
fluxes.
All investigated soil types were C sinks, storing up to 9,6 t CO2eq ha-1 yr-1. As
expected for this well-drained soils, the climate impact of CH4 emissions was negligible on
all plots with mineral and organic fertilization (-0,05 t CO2eq ha-1 yr-1 up to 0,01 t CO2eq
ha-1 yr-1). On minerally fertilized plots, contribution of N2O emissions were very different
and varied between 10% and 43% to the overall climate impact (-9,6 t CO2eq ha-1 yr-1 to
-2,3 t CO2eq ha-1 yr-1). The highest amount was investigated on the deposition plot. For
organic fertilization, N2O emissions increased moderate from 0,02 t CO2eq ha-1 yr-1
(non-fertilized control) with increasing amount of fertilizer to 1,5 t CO2eq ha-1
yr-1.
In contrast to N fertilizer application, the contribution of N2O and CH4 to the overall
climate impact of eroded agriculturally soils in the glacially shaped landscape is very
heterogeneous.
Drösler, M. 2005. Trace Gas Exchange and climatic relevance of bog ecosystems,
Southern Germany, phD-thesis, TU München, München
Livingston, G.P. & Hutchinson, G.L. 1995. Enclosure-based measurement of trace gas
exchange: Applications and sources of error. p. 14-51. In P.A. Matson & Harriss, R.C. (ed.)
Methods in ecology - Biogenic trace gases: Measuring emissions from soil and water.
Blackwell Science, Oxford, England |
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