title: Statistical analysis of nitrous oxide emission factors from pastoral agriculture field trials conducted in New Zealand.
abstract: Between 11 May 2000 and 31 January 2013, 185 field trials were conducted across New Zealand to measure the direct nitrous oxide (N2O) emission factors (EF) from nitrogen (N) sources applied to pastoral soils. The log(EF) data were analysed statistically using a restricted maximum likelihood (REML) method. To estimate mean EF values for each N source, best linear unbiased predictors (BLUPs) were calculated. For lowland soils, mean EFs for dairy cattle urine and dung, sheep urine and dung and urea fertiliser were 1.16 ± 0.19% and 0.23 ± 0.05%, 0.55 ± 0.19% and 0.08 ± 0.02% and 0.48 ± 0.13%, respectively, each significantly different from one another (p < 0.05), except for sheep urine and urea fertiliser. For soils in terrain with slopes >12°, mean EFs were significantly lower. Thus, urine and dung EFs should be disaggregated for sheep and cattle as well as accounting for terrain.
authors.affiliation: AgResearch, Lincoln Research Centre, Private Bag 4749, Christchurch 8140, New Zealand; Lincoln University, Department of Soil and Physical Sciences, P.O. Box 84, Lincoln 7647, New Zealand. Electronic address: frank.kelliher@agresearch.co.nz.
authors.forename: F M
authors.initials: FM
authors.lastname: Kelliher
authors.affiliation: AgResearch, Invermay Research Centre, Private Bag 50034, Mosgiel, New Zealand.
authors.forename: N
authors.initials: N
authors.lastname: Cox
authors.affiliation: AgResearch, Invermay Research Centre, Private Bag 50034, Mosgiel, New Zealand.
authors.forename: T J
authors.initials: TJ
authors.lastname: van der Weerden
authors.affiliation: AgResearch, Invermay Research Centre, Private Bag 50034, Mosgiel, New Zealand.
authors.forename: C A M
authors.initials: CA
authors.lastname: de Klein
authors.affiliation: AgResearch, Ruakura Research Centre, Private Bag 3123, Hamilton 3240, New Zealand.
authors.forename: J
authors.initials: J
authors.lastname: Luo
authors.affiliation: Lincoln University, Department of Soil and Physical Sciences, P.O. Box 84, Lincoln 7647, New Zealand.
authors.forename: K C
authors.initials: KC
authors.lastname: Cameron
authors.affiliation: Lincoln University, Department of Soil and Physical Sciences, P.O. Box 84, Lincoln 7647, New Zealand.
authors.forename: H J
authors.initials: HJ
authors.lastname: Di
authors.affiliation: Manaaki Whenua Landcare Research, Private Bag 11052, Palmerston North 4442, New Zealand.
authors.forename: D
authors.initials: D
authors.lastname: Giltrap
authors.affiliation: Ministry for Primary Industries, P.O. Box 2526, Wellington, New Zealand.
authors.forename: G
authors.initials: G
authors.lastname: Rys
mesh_terms: D000383:Agriculture; D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000706:statistics & numerical data*; D000818:Animals; D002417:Cattle; D004784:Environmental Monitoring / Q000379:methods*; D005308:Fertilizers / Q000706:statistics & numerical data*; D009520:New Zealand; D009584:Nitrogen / Q000032:analysis; D009609:Nitrous Oxide / Q000032:analysis*; D012756:Sheep; D012987:Soil / Q000737:chemistry
chemical_list: D000393:Air Pollutants; D005308:Fertilizers; D012987:Soil; D009609:Nitrous Oxide; D009584:Nitrogen
keywords: Agriculture; Nitrous oxide; Pasture; Soil; Statistics