Nitrous oxide emissions from a fertilized grazed grassland in Ireland

• Published in: International Congress series Vol. 1293; pp. 351 - 354
• Main Authors: Hyde, B.P., Hawkins, M.J., Ryan, M., Carton, O.T.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-07-2006
• Subjects: N fertilizer; Nitrous oxide; Scenario analysis; Scenario analysis; N fertilizer; Nitrous oxide
• ISSN: 0531-5131; 1873-6157
• DOI: 10.1016/j.ics.2006.03.002

A field experiment was undertaken to compare nitrous oxide (N
2O) emissions from a grazed pasture receiving three different nitrogen (N) fertilizer application rates (0, 225 and 390 kg ha
−
1
) and to identify the effects of controlling variables over a 2-year period (2002 and 2003). The N
2O-N losses, expressed as a percent of the N applied, in the cooler and wetter 2002 were 0.2–2.0%. In contrast, the percentage loss in the warmer and drier 2003 (3.5–7.2%) were substantially higher. An empirical model was developed to enable simulations and scenario analysis to be undertaken, assuming various climatic scenarios and N fertilizer application regimes. Results suggest that inter-annual variability due to climatic factors increases with the amount of applied fertilizer N and decreases with frequency of application.