title: Bacteria on leaves: a previously unrecognised source of N2O in grazed pastures.
abstract: Nitrous oxide (N2O) emissions from grazed pastures are a product of microbial transformations of nitrogen and the prevailing view is that these only occur in the soil. Here we show this is not the case. We have found ammonia-oxidising bacteria (AOB) are present on plant leaves where they produce N2O just as in soil. AOB (Nitrosospira sp. predominantly) on the pasture grass Lolium perenne converted 0.02-0.42% (mean 0.12%) of the oxidised ammonia to N2O. As we have found AOB to be ubiquitous on grasses sampled from urine patches, we propose a 'plant' source of N2O may be a feature of grazed grassland.
authors.affiliation: AgResearch Limited, Grasslands Research Centre, Palmerston North, New Zealand.
authors.forename: Saman
authors.initials: S
authors.lastname: Bowatte
authors.affiliation: AgResearch Limited, Grasslands Research Centre, Palmerston North, New Zealand.
authors.forename: Paul C D
authors.initials: PC
authors.lastname: Newton
authors.affiliation: AgResearch Limited, Grasslands Research Centre, Palmerston North, New Zealand.
authors.forename: Shona
authors.initials: S
authors.lastname: Brock
authors.affiliation: AgResearch Limited, Grasslands Research Centre, Palmerston North, New Zealand.
authors.forename: Phil
authors.initials: P
authors.lastname: Theobald
authors.affiliation: AgResearch Limited, Grasslands Research Centre, Palmerston North, New Zealand.
authors.forename: Dongwen
authors.initials: D
authors.lastname: Luo
mesh_terms: D000818:Animals; D001419:Bacteria / Q000302:isolation & purification*; D008129:Lolium / Q000382:microbiology*; D009609:Nitrous Oxide / Q000737:chemistry*; D018515:Plant Leaves / Q000382:microbiology*; D012988:Soil Microbiology
chemical_list: D009609:Nitrous Oxide