• Authors:
    • Naylor,T.
    • Macdonald,B. C. T.
    • Denmead,O. T.
    • Wilson,S.
    • White,I.
    • Moody,P.
    • Griffith,D. W. T.
    • Salter,B.
    • Wang, T.
  • Source: Proceedings of the 2008 Conference of the Australian Society of Sugar Cane Technologists
  • Volume: 30
  • Year: 2008
  • Authors:
    • Baigent, R.
    • Kelly, K. B.
    • Phillips, F. A.
  • Source: Australian Journal of Experimental Agriculture
  • Volume: 48
  • Year: 2008
  • Authors:
    • Barton, L.
    • Kiese, R.
    • Gatter, D.
    • Butterbach-Bahl, K.
    • Buck, R.
    • Hinz, C.
    • Murphy, D. V.
  • Source: Global Change Biology
  • Volume: 14
  • Issue: 1
  • Year: 2008
  • Summary: Understanding nitrous oxide (N2O) emissions from agricultural soils in semi-arid regions is required to better understand global terrestrial N2O losses. Nitrous oxide emissions were measured from a rain-fed, cropped soil in a semi-arid region of south-western Australia for one year on a sub-daily basis. The site included N-fertilized (100 kg N ha−1 yr−1) and nonfertilized plots. Emissions were measured using soil chambers connected to a fully automated system that measured N2O using gas chromatography. Daily N2O emissions were low (−1.8 to 7.3 g N2O-N ha−1 day−1) and culminated in an annual loss of 0.11 kg N2O-N ha−1 from N-fertilized soil and 0.09 kg N2O-N ha−1 from nonfertilized soil. Over half (55%) the annual N2O emission occurred from both N treatments when the soil was fallow, following a series of summer rainfall events. At this time of the year, conditions were conducive for soil microbial N2O production: elevated soil water content, available N, soil temperatures generally >25 °C and no active plant growth. The proportion of N fertilizer emitted as N2O in 1 year, after correction for the ‘background’ emission (no N fertilizer applied), was 0.02%. The emission factor reported in this study was 60 times lower than the IPCC default value for the application of synthetic fertilizers to land (1.25%), suggesting that the default may not be suitable for cropped soils in semi-arid regions. Applying N fertilizer did not significantly increase the annual N2O emission, demonstrating that a proportion of N2O emitted from agricultural soils may not be directly derived from the application of N fertilizer. ‘Background’ emissions, resulting from other agricultural practices, need to be accounted for if we are to fully assess the impact of agriculture in semi-arid regions on global terrestrial N2O emissions.
  • Authors:
    • Kelly, K.
    • Armstrong, R.
    • Phillips, F.
    • Officer, S. J.
  • Source: 14th Australian Agronomy Conference
  • Year: 2008
  • Authors:
    • Aarndt, S. K.
    • Eckard, R.
    • Livesley, S. J.
  • Source: Plant and Soil
  • Volume: 309
  • Issue: 1-2
  • Year: 2008
  • Authors:
    • Chen, D.
    • Suter, H.
  • Source: Milk, Money and Management
  • Year: 2008
  • Authors:
    • Edis, R.
    • Islam, A.
    • Chen, D.
    • Suter, H.
  • Source: Soil: The Living Skin of Planet Earth
  • Year: 2008
  • Authors:
    • Graham, J.
    • Kelly, K.
    • Li, Y.
    • Chen, D.
    • Edis, R.
    • Turner, D. A.
  • Source: The 2008 Joint Annual Meeting
  • Year: 2008
  • Authors:
    • Phillips, F.
    • Kelly, K.
    • Leuning, R.
    • Edis, R. B.
    • Galbally, I. E.
    • Chen, D.
    • Turner, D. A.
  • Source: Plant and Soil
  • Volume: 309
  • Issue: 1-2
  • Year: 2008
  • Authors:
    • Dalal, R. C.
    • Salter, B.
    • Reeves, S. H.
    • Moody, P. W.
    • Wang, W. J.
  • Source: Proceedings of Australian Society of Sugarcane Technologists
  • Volume: 30
  • Year: 2008