Sources of nitrous oxide from intensively managed pasture soils: the hole in the pipe
Rainfall and irrigation trigger large pulses of the powerful greenhouse gas N _2 O from intensively managed pastures, produced via multiple, simultaneously occurring pathways. These N _2 O pulses can account for a large fraction of total N _2 O losses, demonstrating the importance to determine magni...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2021-01-01
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| Series: | Environmental Research Letters |
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| Online Access: | https://doi.org/10.1088/1748-9326/abfde7 |
| _version_ | 1797747654876200960 |
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| author | Johannes Friedl Clemens Scheer Daniele De Rosa Christoph Müller Peter R Grace David W Rowlings |
| author_facet | Johannes Friedl Clemens Scheer Daniele De Rosa Christoph Müller Peter R Grace David W Rowlings |
| author_sort | Johannes Friedl |
| collection | DOAJ |
| description | Rainfall and irrigation trigger large pulses of the powerful greenhouse gas N _2 O from intensively managed pastures, produced via multiple, simultaneously occurring pathways. These N _2 O pulses can account for a large fraction of total N _2 O losses, demonstrating the importance to determine magnitude and source partitioning of N _2 O under these conditions. This study investigated the response of different pathways of N _2 O production to wetting across three different textured pasture soils. Soil microcosms were fertilised with an ammonium nitrate (NH _4 NO _3 ) solution which was either single or double ^15 N labelled, wetted to four different water-filled pore space (WFPS) levels, and incubated over two days. The use of a ^15 N pool mixing model together with soil N gross transformations enabled the attribution of N _2 O to specific pathways, and to express N _2 O emissions as a fraction of the underlying N transformation. Denitrification and nitrification mediated pathways contributed to the production of N _2 O in all soils, regardless of WFPS. Denitrification was the main pathway of N _2 O production accounting for >50% of cumulative N _2 O emissions even at low WFPS. The contribution of autotrophic nitrification to N _2 O emissions decreased with the amount of wetting, while the contribution of heterotrophic nitrification remained stable or increased. Following the hole-in-the-pipe model, 0.1%–4% of nitrified N was lost as N _2 O, increasing exponentially with WFPS, while the percentage of denitrified N emitted as N _2 O decreased, providing critical information for the representation of N _2 O/WFPS relationships in simulation models. Our findings demonstrate that the wetting of pasture soils promotes N _2 O production via denitrification and via the oxidation of organic N substrates driven by high carbon and N availability upon wetting. The large contribution of heterotrophic nitrification to N _2 O emissions should be considered when developing N _2 O abatement strategies, seeking to reduce N _2 O emissions in response to rainfall and irrigation from intensively managed pastures. |
| first_indexed | 2024-03-12T15:54:41Z |
| format | Article |
| id | doaj.art-5aea203987d34841b31bac41c9cb783f |
| institution | Directory Open Access Journal |
| issn | 1748-9326 |
| language | English |
| last_indexed | 2024-03-12T15:54:41Z |
| publishDate | 2021-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | Environmental Research Letters |
| spelling | doaj.art-5aea203987d34841b31bac41c9cb783f2023-08-09T14:59:29ZengIOP PublishingEnvironmental Research Letters1748-93262021-01-0116606500410.1088/1748-9326/abfde7Sources of nitrous oxide from intensively managed pasture soils: the hole in the pipeJohannes Friedl0https://orcid.org/0000-0003-0468-916XClemens Scheer1https://orcid.org/0000-0001-5396-2076Daniele De Rosa2https://orcid.org/0000-0002-0441-7722Christoph Müller3Peter R Grace4https://orcid.org/0000-0003-4136-4129David W Rowlings5https://orcid.org/0000-0002-1618-9309Centre for Agriculture and the Bioeconomy, Queensland University of Technology , Brisbane, QLD 4000, AustraliaCentre for Agriculture and the Bioeconomy, Queensland University of Technology , Brisbane, QLD 4000, Australia; Institute for Meteorology and Climate Research (IMK-IFU) Karlsruhe Institute of Technology (KIT) , Garmisch-Partenkirchen, GermanyCentre for Agriculture and the Bioeconomy, Queensland University of Technology , Brisbane, QLD 4000, AustraliaInstitute of Plant Ecology (IFZ), Justus-Liebig University , Giessen, Germany; School of Biology and Environmental Science, University College Dublin , Belfield, Dublin, IrelandCentre for Agriculture and the Bioeconomy, Queensland University of Technology , Brisbane, QLD 4000, AustraliaCentre for Agriculture and the Bioeconomy, Queensland University of Technology , Brisbane, QLD 4000, AustraliaRainfall and irrigation trigger large pulses of the powerful greenhouse gas N _2 O from intensively managed pastures, produced via multiple, simultaneously occurring pathways. These N _2 O pulses can account for a large fraction of total N _2 O losses, demonstrating the importance to determine magnitude and source partitioning of N _2 O under these conditions. This study investigated the response of different pathways of N _2 O production to wetting across three different textured pasture soils. Soil microcosms were fertilised with an ammonium nitrate (NH _4 NO _3 ) solution which was either single or double ^15 N labelled, wetted to four different water-filled pore space (WFPS) levels, and incubated over two days. The use of a ^15 N pool mixing model together with soil N gross transformations enabled the attribution of N _2 O to specific pathways, and to express N _2 O emissions as a fraction of the underlying N transformation. Denitrification and nitrification mediated pathways contributed to the production of N _2 O in all soils, regardless of WFPS. Denitrification was the main pathway of N _2 O production accounting for >50% of cumulative N _2 O emissions even at low WFPS. The contribution of autotrophic nitrification to N _2 O emissions decreased with the amount of wetting, while the contribution of heterotrophic nitrification remained stable or increased. Following the hole-in-the-pipe model, 0.1%–4% of nitrified N was lost as N _2 O, increasing exponentially with WFPS, while the percentage of denitrified N emitted as N _2 O decreased, providing critical information for the representation of N _2 O/WFPS relationships in simulation models. Our findings demonstrate that the wetting of pasture soils promotes N _2 O production via denitrification and via the oxidation of organic N substrates driven by high carbon and N availability upon wetting. The large contribution of heterotrophic nitrification to N _2 O emissions should be considered when developing N _2 O abatement strategies, seeking to reduce N _2 O emissions in response to rainfall and irrigation from intensively managed pastures.https://doi.org/10.1088/1748-9326/abfde7nitrous oxidegreen house gas emissionsclimate changedenitrificationnitrificationpastures |
| spellingShingle | Johannes Friedl Clemens Scheer Daniele De Rosa Christoph Müller Peter R Grace David W Rowlings Sources of nitrous oxide from intensively managed pasture soils: the hole in the pipe Environmental Research Letters nitrous oxide green house gas emissions climate change denitrification nitrification pastures |
| title | Sources of nitrous oxide from intensively managed pasture soils: the hole in the pipe |
| title_full | Sources of nitrous oxide from intensively managed pasture soils: the hole in the pipe |
| title_fullStr | Sources of nitrous oxide from intensively managed pasture soils: the hole in the pipe |
| title_full_unstemmed | Sources of nitrous oxide from intensively managed pasture soils: the hole in the pipe |
| title_short | Sources of nitrous oxide from intensively managed pasture soils: the hole in the pipe |
| title_sort | sources of nitrous oxide from intensively managed pasture soils the hole in the pipe |
| topic | nitrous oxide green house gas emissions climate change denitrification nitrification pastures |
| url | https://doi.org/10.1088/1748-9326/abfde7 |
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