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| Titel |
Effects of fermentation slurry and erosion on greenhouse gas fluxes in a young moraine landscape of NE Germany |
| VerfasserIn |
Ulrike Hagemann, Madlen Pohl, Michael Sommer, Jürgen Augustin |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250053286
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| Zusammenfassung |
| A large part of the European landscape is used for agricultural production, but few studies
have provided comprehensive datasets on greenhouse gas fluxes of agricultural lands, which
are required to develop ecosystem and landscape models (Smith et al. 2010). In particular, the
impact of energy crops – often associated with the application of fermentation slurry – and of
management-induced erosion and deposition processes on ecosystem gas exchange and the
carbon budget of arable sites needs to be investigated in the glacially shaped and
agriculturally dominated young moraine landscape of north-eastern Germany. In an
interdisciplinary approach, the CarboZALF-D project investigates the impact of various
factors such as crop, fertiliser, soil type, and erosion on greenhouse gas fluxes and carbon
dynamics in a research site located near Prenzlau, Germany. The current study compares the
greenhouse gas balance of plots categorized by different fertilisation regimes and
erosion-induced soil types. Fertilisation treatments encompassed sites with 100% organic
(fermentation slurry), 50% mineral-50% organic, and 100% mineral fertilisation (reference).
Erosion-induced soil types included an eroded Luvisol (erosion), a Colluvic Regosol
(deposition), and a non-eroded Haplic Luvisol (reference). All sites were planted with corn
(Zea mays L.).
Starting in spring 2010, greenhouse gas fluxes (three replicates per site) were measured
using a non-flow-through non-steady-state chamber system (Livingston and Hutchinson,
1995) with interval (N2O, CH4; gas chromatograph) and continuous sampling (CO2; LI-840,
LI-COR Inc.; Drösler 2005). Air and soil temperatures and photosynthetic active radiation
(PAR) were recorded simultaneously to each individual flux measurement. Measurements of
N2O and CH4 were conducted once every 2-3 weeks. CO2 measurement campaigns were
conducted every 3-4 weeks and encompassed repeated measurements of ecosystem
respiration (Reco; opaque chamber) and net ecosystem exchange (NEE; transparent chamber).
Measured flux rates were linearly interpolated between measurement campaigns (N2O,
CH4), or modelled based on continuously logged soil temperatures (Reco) or PAR
(NEE).
The application of fermentation slurry considerably affected the N2O efflux. Plots with
100% slurry fertilisation had significantly higher annual cumulative N2O emissions
(6.8 kg N ha-1) than plots with 100% mineral fertilisation (1.4 kg N ha-1), with
intermediate values at plots with mixed fertilisation (4.7 kg N ha-1). The CH4 efflux was
near zero (-0.2 to 0.1 kg C ha-1) regardless of fertilisation type. Rates of Reco tended to be
higher in sites with 100% organic fertilisation. Erosion also had a significant impact on
greenhouse gas fluxes. Cumulative N2O emissions showed an increasing trend from the
eroded Luvisol (0.6 kg N ha-1) to the non-eroded Luvisol (1.4 kg N ha-1) to the
Colluvic Regosol (4.9 kg N ha-1). The Colluvic Regosol also featured the highest uptake
of CH4 (-0.9 kg C ha-1). While NEE rates showed little influence of either fertilisation or
soil type, Recotended to be highest on the Colluvic Regosol, with no consistent differences
between the eroded and non-eroded Luvisol plots. The high observed spatial and temporal
variability is typical of ecosystem gas fluxes. Consequently, long-term studies such as
CarboZALF-D are required to accurately assess the carbon dynamics of agricultural
landscapes.
Drösler, M. 2005. Trace Gas Exchange and climatic relevance of bog ecosystems,
Southern Germany, Dissertation, TU München, Munich, Germany.
Livingston, G.P., and G.L. Hutchinson. 1995. Enclosure-based measurement of trace gas
exchange: Applications and sources of error. p. 14-51. In P.A. Matson and R.C. Harriss (ed.)
Methods in ecology - Biogenic trace gases: Measuring emissions from soil and water.
Blackwell Science, Oxford, England.
With contributions from Sylvia Koszinski, Wilfried Hierold, Detlef Deumlich, Gernot
Verch, Johannes Hufnagel (ZALF e.V.) |
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