Biochar amendment suppresses N2 O emissions but has no impact on 15 N site preference in an anaerobic soil.
Rapid Commun Mass Spectrom
; 33(2): 165-175, 2019 Jan 30.
Article
em En
| MEDLINE
| ID: mdl-30304571
ABSTRACT
RATIONALE Biochar amendments often decrease N2 O gas production from soil, but the mechanisms and magnitudes are still not well characterized since N2 O can be produced via several different microbial pathways. We evaluated the influence of biochar amendment on N2 O emissions and N2 O isotopic composition, including 15 N site preference (SP) under anaerobic conditions. METHODS:
An agricultural soil was incubated with differing levels of biochar. Incubations were conducted under anaerobic conditions for 10 days with and without acetylene, which inhibits N2 O reduction to N2 . The N2 O concentrations were measured every 2 days, the SPs were determined after 5 days of incubation, and the inorganic nitrogen concentrations were measured after the incubation.RESULTS:
The SP values with acetylene were consistent with N2 O production by bacterial denitrification and those without acetylene were consistent with bacterial denitrification that included N2 O reduction to N2 . There was no effect of biochar on N2 O production in the presence of acetylene between day 3 and day 10. However, in the absence of acetylene, soils incubated with 4% biochar produced less N2 O than soils with no biochar addition. Different amounts of biochar amendment did not change the SP values.CONCLUSIONS:
Our study used N2 O emission rates and SP values to understand biochar amendment mechanisms and demonstrated that biochar amendment reduces N2 O emissions by stimulating the last step of denitrification. It also suggested a possible shift in N2 O-reducing microbial taxa in 4% biochar samples.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Rapid Commun Mass Spectrom
Ano de publicação:
2019
Tipo de documento:
Article
País de afiliação:
Estados Unidos