Abstract
Summary Nitrous oxide (N2O) is a potent, globally important, greenhouse gas, predominantly released from agricultural soils during nitrogen (N) cycling. Arbuscular mycorrhizal fungi (AMF) form a mutualistic symbiosis with two‐thirds of land plants, providing phosphorus and/or N in exchange for carbon. As AMF acquire N, it was hypothesized that AMF hyphae may reduce N2O production. AMF hyphae were either allowed (AMF) or prevented (nonAMF) access to a compartment containing an organic matter and soil patch in two independent microcosm experiments. Compartment and patch N2O production was measured both before and after addition of ammonium and nitrate.In both experiments, N2O production decreased when AMF hyphae were present before inorganic N addition. In the presence of AMF hyphae, N2O production remained low following ammonium application, but increased in the nonAMF controls. By contrast, negligible N2O was produced following nitrate application to either AMF treatment.Thus, the main N2O source in this system appeared to be via nitrification, and the production of N2O was reduced in the presence of AMF hyphae. It is hypothesized that AMF hyphae may be outcompeting slow‐growing nitrifiers for ammonium. This has significant global implications for our understanding of soil N cycling pathways and N2O production.
Highlights
Agricultural soils are a major source of the globally important greenhouse gas, nitrous oxide (N2O), a gaseous product of the nitrogen (N) cycle (Singh et al, 2010; Hartmann et al, 2013)
To test the hypothesis that N2O production was reduced in the presence of Arbuscular mycorrhizal fungi (AMF) hyphae, two experiments were established under glasshouse conditions using compartmented microcosm units
Expt 1 was designed to determine the impact of AMF hyphae on N2O production, whereas Expt 2 was designed to determine whether AMF hyphae affected N2O produced by nitrification and/or denitrification
Summary
Agricultural soils are a major source of the globally important greenhouse gas, nitrous oxide (N2O), a gaseous product of the nitrogen (N) cycle (Singh et al, 2010; Hartmann et al, 2013). Other commonly occurring soil bacteria and archaea may utilize exogenous N2O, including under aerobic conditions, even though they lack the preceding steps in the denitrification pathway (Sanford et al., 2012; Jones et al, 2014). It follows that the net N2O emitted from soils will be influenced by the presence of microorganisms
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
