Improved prediction of farm nitrous oxide emission through an understanding of the interaction among climate extremes, soil nitrogen dynamics and irrigation water
Article
Article Title | Improved prediction of farm nitrous oxide emission through an understanding of the interaction among climate extremes, soil nitrogen dynamics and irrigation water |
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ERA Journal ID | 5850 |
Article Category | Article |
Authors | Maraseni, Tek (Author) and Kodur, Shreevatsa (Author) |
Journal Title | Journal of Environmental Management |
Journal Citation | 248, pp. 1-7 |
Article Number | 109278 |
Number of Pages | 7 |
Year | 2019 |
Publisher | Elsevier |
Place of Publication | United Kingdom |
ISSN | 0301-4797 |
1093-0191 | |
1095-8630 | |
Digital Object Identifier (DOI) | https://doi.org/10.1016/j.jenvman.2019.109278 |
Web Address (URL) | https://www.sciencedirect.com/science/article/pii/S0301479719309806 |
Abstract | Reducing nitrous oxide (N2O) emissions from agriculture soils is crucial, as it accounts for 5.6-6.8% of global anthropogenic emissions. This study aims to understand the interaction among climate, soil nitrogen (N) and applied N on N2O emissions from the irrigated cotton farming system and its implications on farm economics. We conducted simulations for 116 years (1900-2015) and assessed the effect of different N-fertiliser application rates, initial soil nitrate (NO3) N levels and rainfall conditions on N2O emissions, N2O emission factors (EFs) and financial returns (with and without N2O costs). Results showed the following. 1) The proportional impact of higher N fertiliser rates on soil N2O emissions was greater when initial soil N level was lower (5 mg NO3 kg(-1)) than higher (35 mg NO3 kg(-1)). However, the volume of impact was greater under higher initial soil N levels. 2) The relationship between N fertiliser rates and the EFs (range 0.03-7.2%) was not linear but bell-shaped. 3) Fertiliser N requirements increased with rainfall and decreased with initial soil N. Accordingly, the cotton returns for the driest rainfall condition ( < 10th percentile) were maximum at 300, 250 and 150 kg N ha(-1) for initial soil N of 5, 20 and 35 mg NO3 kg(-1). For the wettest rainfall condition ( > 90th percentile), these rates were 50 kg ha(-1) higher across the initial soil N conditions. Any additional application of N-fertiliser above these rates was counterproductive. 4) Inclusion of N2O cost into farm economics reduced the annual returns by up to $39 ha(-1), but the optimal fertiliser application rates remain the same. 5) Optimising N fertiliser rates to soil N and rainfall conditions increased the annual returns by up to $303 ha(-1), with a further increase of $15 ha(-1) from fertiliser use efficiency when the Australian Government incentives under the $2.55 billion dollar Emission Reduction Fund program was considered. These findings suggest that N-fertiliser application rates and N2O emission mitigation strategies need further refinements specific to prevailing soil and climate variabilities. |
Keywords | cotton, nitrous oxide, emissions factor, emissions reduction fund, profit maximisation |
ANZSRC Field of Research 2020 | 300499. Crop and pasture production not elsewhere classified |
Byline Affiliations | Centre for Sustainable Agricultural Systems |
Institution of Origin | University of Southern Queensland |
https://research.usq.edu.au/item/q56w0/improved-prediction-of-farm-nitrous-oxide-emission-through-an-understanding-of-the-interaction-among-climate-extremes-soil-nitrogen-dynamics-and-irrigation-water
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