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| Titel |
Pruning removal from orchards for energetic use: impacts on SOC and CO2-emissions |
| VerfasserIn |
Sonja Germer, Giacomo Lanza, Sarah Schleicher, Wolf-Anno Bischoff, Maider Gomez Palermo, Fernando Sebastian Nogues, Jürgen Kern |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250133914
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| Publikation (Nr.) |
 EGU/EGU2016-14579.pdf |
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| Zusammenfassung |
| Prunings of orchards are usually burnt or left on the soil for nutrient and
organic carbon recycling. Recently the interest rose to remove prunings for
energetic use. Effects of pruning removal on soil physical and chemical
characteristics are expected rather in the long term. Under certain
circumstances, however, soil characteristics as organic carbon content and
greenhouse gas emissions might change on the short term as our literature
review revealed.
The main objective of this research was to determine if pruning removal from
orchards changes soil organic carbon content and CO$_{2}$-emission from
soils in the short-term. We compared six different study sites in Spain,
France and Germany in terms of impacts on soil chemistry (total and organic
carbon) and four sites for impacts on CO$_{2}$-emissions during 2 years. A
block design was set up over two rows each with two parcels where we removed
prunings and two parcels where prunings were chipped and left on the soil
(n=4). As soil characteristics may vary between tree rows and interrows of
orchards, we sampled both positions separately. To assess the relative
contribution of CO$_{2}$ emissions from carbonate and organic material, the
isotopic signature of CO$_{2}$ ($\delta ^{13}$CO$_{$_2$}) was analyzed for
one orchard. Our results show that pruning removal could significantly
decrease soil organic carbon in the tree row after 2 years of pruning
removal, as found for one German orchard. No treatment effects were detected
on CO$_{2}$-emissions. We found, however, differences in CO$_{2}$ emissions
according to the sampling position in tree rows and interrows. More CO$_{2}$
emission was found for that row position per orchard with higher soil
organic carbon. Isotopic CO$_{2}$ signature indicated that elevated CO$_{2}$
emissions were rather linked to higher microbial decomposition or root
respiration than to the release from carbonates. As no pruning wood
decomposition effect on CO$_{2}$ emissions were apparent, but soil with
higher organic carbon released more CO$_{2}$, it is expected that due to
slow soil organic carbon decrease several years of pruning removal are
needed before a decrease of soil CO$_{2 }$emissions might be detectable. In
addition, the loss through dissolved organic carbon leaching should be
assessed in future studies. |
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