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| Titel |
The effect of biochar amendment on the soil microbial community - PLFA analyses and 13C labeling results |
| VerfasserIn |
A. Watzinger, S. Feichtmair, F. Rempt, E. Anders, B. Wimmer, B. Kitzler, S. Zechmeister-Boltenstern, Micha Horacek, F. Zehetner, S. Kloss, S. Richoz, G. Soja |
| 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 |
250059648
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| Zusammenfassung |
| The effects of biochar amendment on plant growth and on the chemical / physical soil
characteristics are well explored but only few studies have investigated the impact on soil
microorganisms.
The response of the soil microbial community to biochar amendment was investigated by
phospholipid fatty acid (PLFA) analysis in (i) a large scale pot experiment, (ii) a small scale
pot experiment using 13C labeled biochar and (iii) an incubation study using 13C labeled
biochar. In the large scale pot experiment, three different agricultural soils from Austria
(Planosol, Cambisol, Chernozem) and four different types of biochar were investigated.
In total, 25 treatments with 5 replicates each were set up and monitored over a
year.
The results from the pot experiments showed no significant influence of biochar amendment
on the total microbial biomass in the first 100 days after biochar addition. However,
discriminant analysis showed a distinction of biochar and control soils as well as a strong
effect of the pyrolysis temperature on the microbial composition. The effect of biochar was
dependent on the type of soil. In the Planosol, some PLFAs were affected positively,
especially when adding biochar with a low pyrolysis temperature, in the first month. In the
long term, microbial community composition altered. Growth of fungi and gram negative
bacteria was enhanced. In the Chernozem, PLFAs from various microbial groups decreased in
the long term.
Variability in the incubation study was low. Consequently, many PLFAs were significantly
affected by biochar amendment. Again, in the Planosol, gram negative bacteria,
actinomycetes and, after 2 weeks, gram positive bacteria increased under biochar amendment
whereas in the chernozem total microbial biomass and gram positive bacteria were negatively
affected in the long term.
The 13C labeling studies confirmed the low degradability of the biochar, i.e. no alteration of
the content and the δ13C in the soil organic matter within 100 days, decreased CO2
emission after biochar addition and little 13C signature from the biochar in the respired
CO2.
The uptake of the labeled biochar into the microbial PLFAs was analysed and will provide an
evidence if biochar was used as a carbon source. In addition, the long term effect of biochar
amendment (beyond 100 days) on the soil microbial community is currently investigated.
These results will be also presented in the oncoming meeting. |
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