Biochar amendment suppresses N2O emissions but has no impact on 15N site preference in an anaerobic soil. (19th December 2018)

• Record Type: Journal Article
• Authors: Hyodo, Ayumi; Malghani, Saadatullah; Zhou, Yong; Mushinski, Ryan M.; Toyoda, Sakae; Yoshida, Naohiro; Boutton, Thomas W.; West, Jason B.
• Is Part Of: Rapid communications in mass spectrometry. Volume 33:Number 2(2019)
• Page Start: 165
• Page End: 175
• Publication Date: 2018-12-19
• Subjects: Mass spectrometry -- Periodicals; 543.65
• DOI: 10.1002/rcm.8305
• Languages: English
• ISSNs: 0951-4198

Abstract

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.