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| Titel |
Identification of long-term carbon sequestration in soils with historical inputs of biochar using novel stable isotope and spectroscopic techniques |
| VerfasserIn |
Maria C. Hernandez-Soriano, Bart Kerré, Brieuc Hardy, Joseph Dufey, Erik Smolders |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250072577
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| Zusammenfassung |
| Biochar is the collective term for organic matter (OM) that has been produced by pyrolysis of
biomass, e.g. during production of charcoal or during natural processes such as bush fires.
Biochar production and application is now suggested as one of the economically feasible
options for global C-sequestration strategies. The C-sequestration in soil through application
of biochar is not only related to its persistence (estimated lifetime exceeds 1000 year in soil),
but also due to indirect effects such as its potential to adsorb and increase OM stability in
soil.
Historical charcoal production sites that had been in use >200 years ago in beech/oak
forests have been localized in the south of Belgium. Aerial photography identified black spots
in arable land on former forest sites. Soil sampling was conducted in an arable field used for
maize production near Mettet (Belgium) where charcoal production was intensive until late
18th century. Soils were sampled in a horizontal gradient across the ‘black soils’ that extend
of few decametres, collecting soil from the spots (Biochar Amended, BA) as well as from the
non-biochar amended (NBA).
Stable C isotope composition was used to estimate the long-term C-sequestration derived
from crops in these soils where maize had been produced since about 15 years.
Because C in the biochar originates in forest wood (C3 plants), its isotopic signature
(δ13C) differs from the maize (a C4 plant). The C and N content and the δ13C were
determined for bulk soil samples and for microaggregate size fractions separated by
wet sieving. Fourier Transform Infrared Spectroscopy (FTIR) coupled to optical
microscopy was used to obtaining fingerprints of biochar and OM composition for soil
microaggregates.
The total C content in the BA soil (5.5%) and the C/N ratio (16.9) were higher than for
NBA (C content 2.7%; C/N ratio 12.6), which confirms the persistence of OM in the BA. The
average isotopic signature of bulk soil from BA (-26.08) was slightly but significantly higher
(p |
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