Biochar amendment suppresses N2 O emissions but has no impact on 15 N site preference in an anaerobic soil. Academic Article uri icon


  • 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 10days with and without acetylene, which inhibits N2 O reduction to N2 . The N2 O concentrations were measured every 2days, the SPs were determined after 5days 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.

published proceedings

  • Rapid Commun Mass Spectrom

altmetric score

  • 7.1

author list (cited authors)

  • Hyodo, A., Malghani, S., Zhou, Y., Mushinski, R. M., Toyoda, S., Yoshida, N., Boutton, T. W., & West, J. B.

citation count

  • 2

complete list of authors

  • Hyodo, Ayumi||Malghani, Saadatullah||Zhou, Yong||Mushinski, Ryan M||Toyoda, Sakae||Yoshida, Naohiro||Boutton, Thomas W||West, Jason B

publication date

  • January 2019