Nitrous oxide emissions from irrigated wheat in Australia: impact of irrigation management
- 685 Downloads
Background and aims
Irrigation management affects soil water dynamics as well as the soil microbial carbon and nitrogen turnover and potentially the biosphere-atmosphere exchange of greenhouse gasses (GHG). We present a study on the effect of three irrigation treatments on the emissions of nitrous oxide (N2O) from irrigated wheat on black vertisols in South-Eastern Queensland, Australia.
Soil N2O fluxes from wheat were monitored over one season with a fully automated system that measured emissions on a sub-daily basis. Measurements were taken from 3 subplots for each treatment within a randomized split-plot design.
Highest N2O emissions occurred after rainfall or irrigation and the amount of irrigation water applied was found to influence the magnitude of these “emission pulses”. Daily N2O emissions varied from −0.74 to 20.46 g N2O-N ha−1 day−1 resulting in seasonal losses ranging from 0.43 to 0.75 kg N2O-N ha−1 season − 1 for the different irrigation treatments. Emission factors (EF = proportion of N fertilizer emitted as N2O) over the wheat cropping season, uncorrected for background emissions, ranged from 0.2 to 0.4 % of total N applied for the different treatments. Highest seasonal N2O emissions were observed in the treatment with the highest irrigation intensity; however, the N2O intensity (N2O emission per crop yield) was highest in the treatment with the lowest irrigation intensity.
Our data suggest that timing and amount of irrigation can effectively be used to reduce N2O losses from irrigated agricultural systems; however, in order to develop sustainable mitigation strategies the N2O intensity of a cropping system is an important concept that needs to be taken into account.
KeywordsNitrous oxide emissions Irrigation management Fertilisation Emission factor Nitrous oxide intensity
We thank Geoff Robinson for his valuable help in the field measuring campaign. The Department of Employment, Economic Development & Innovation (DEEDI) for providing the study site and the farm staff for planting and harvesting the experimental plots. This research was undertaken as part of the national Nitrous Oxide Research Program (NORP) funded by the Grains Research and Development Corporation (GRDC) and Department of Agriculture, Fishery and Forestry (DAFF).
We also thank two anonymous reviewers for valuable comments on an earlier version of the manuscript.
- ANGA (2010) Australian National Greenhouse Accounts In National Inventory Report 2008. Department of Climate Change and Energy Efficiency.Google Scholar
- Barton L, Kiese R, Gatter D, Butterbach-Bahl K, Buck R, Hinz C, Murphy DV (2008) Nitrous oxide emissions from a cropped soil in a semi-arid climate. Glob Change Biol 14:177–192Google Scholar
- Bouwman AF, Boumans LJM, Batjes NH (2002) Modeling global annual N2O and NO emissions from fertilized fields. Global Biogeochemical Cycles 16.Google Scholar
- Bryan B, Marvanek S (2004) Quantifying and Valuing Land Use Change for Integrated Catchment Management Evaluation in the Murray-Darling Basin 1996/97–2000/01. CSIRO Land and Water, AdelaideGoogle Scholar
- Carter MR, Gregorich EG (2008) Soil sampling and methods of analysis. Canadian Society of Soil Science.Google Scholar
- FAO (1996) Rome declaration on world food security and worldfood summit plan of action. Food and Agriculture Organization of the United Nations, RomeGoogle Scholar
- IPPC (2006) Guidelines for National Greenhouse Gas Inventories, Prepared by the National Greenhouse Gas Inventories Programme. Ed. BL Eggleston HS, Miwa K, Ngara T and Tanabe K, IGES, JapanGoogle Scholar
- Isbell RF (2002) The Australian soil classification. CSIRO, MelbourneGoogle Scholar
- Ortiz-Monasterio I, Matson PA, Panek J, Naylor RL (1996) Nitrogen fertilizer management for N2O and NO emissions in Mexican irrigated wheat. In Transactions 9th Nitrogen Workshop. pp 531–534, Braunschweig, GermanyGoogle Scholar
- Schulze ED, Luyssaert S, Ciais P, Freibauer A, Janssens IA, Soussana JF, Smith P, Grace J, Levin I, Thiruchittampalam B, Heimann M, Dolman AJ, Valentini R, Bousquet P, Peylin P, Peters W, Rodenbeck C, Etiope G, Vuichard N, Wattenbach M, Nabuurs GJ, Poussi Z, Nieschulze J, Gash JH, CarboEurope T (2009) Importance of methane and nitrous oxide for Europe’s terrestrial greenhouse-gas balance. Nat Geosci 2:842–850CrossRefGoogle Scholar
- Smith P, Martino D, Cai Z, Gwary D, Janzen H, Kumar P, McCarl B, Ogle S, O’Mara F, Rice C, Scholes B, Sirotenko O (2007) Agriculture. In: Metz B, Davidson OR, Bosch PR, Dave R, Meyer LA (eds) Climate Change 2007: Mitigation. Contribution of Working Group III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, United KingdomGoogle Scholar
- US-EPA (2006) Global Anthropogenic Non-CO2 Greenhouse Gas Emissions: 1990-2020. United States Environmental Protection Agency, EPA 430-R-06-003, Washington, D.C.Google Scholar