2008 Joint Annual Meeting (5-9 Oct. 2008): Simulating the Impact of Climatic Variability on N2O Emissions from a Rain-Fed Wheat-Cropped Soil in a Semi-Arid Climate.
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582-7 Simulating the Impact of Climatic Variability on N2O Emissions from a Rain-Fed Wheat-Cropped Soil in a Semi-Arid Climate.



Monday, 6 October 2008: 10:15 AM
George R. Brown Convention Center, 370C
Deli Chen, Resource Management & Geography, University of Melbourne, Royal Pde, Parkville, Melbourne, Australia, Yong Li, The University Of Melbourne, School of Resource Management, Land and Food Resources, Parkville, 3010, Australia and Louise Barton, Univ. of Western Australia, Univ. of Western Australia, School of Plant Biology (M084), Nedlands, 6009, Australia
The Water and Nitrogen Management model (WNMM) was applied to simulate N2O emissions from a rain-fed and wheat-cropped system on a sandy duplex soil at Cunderdin, Western Australia, Australia from May 2005 to May 2007. WNMM satisfactorily simulated crop growth, soil water content and mineral N contents of 0-10 cm topsoil, soil temperatures at depths and N2O emissions from the soil, compared with the field observations during calibration and validation. About 89% of total N2O emissions were estimated as nitrification-induced, according to WNMM simulation for this semi-arid and wheat-cropped system. The calibrated and validated WNMM was then deployed to simulate N2O emissions from this soil from 1970 to 2006 for seven scenarios of N fertiliser application at Cunderdin. This sensitivity test found that the annual N2O emissions for this rain-fed and wheat-cropped system were significantly correlated to annual average minimum air temperature (r=0.12), annual pan evaporation (r=0.10), N fertiliser application rate (r=0.91) and wheat yield (r=0.35). Based on this 37-year simulation, multivariate regression models for estimating annual N2O emissions were developed to account for climatic variation (including annual pan evaporation and rainfall) for this rain-fed and wheat-cropped system in Western Australia, which explained over 84% of yearly variations of annual N2O emissions predicted by WNMM.
See more of: Soil Biology and Soil Nitrogen
See more of: S03 Soil Biology & Biochemistry