Denitrification and Nitrous Oxide Emissions in Annual Croplands, Perennial Grass Buffers, and Restored Perennial Grasslands

dc.contributor.author Iqbal, Javed
dc.contributor.author Parkin, Timothy
dc.contributor.author Castellano, Michael
dc.contributor.author Zhou, Xiaobo
dc.contributor.author Helmers, Matthew
dc.contributor.department Leopold Center for Sustainable Agriculture
dc.contributor.department Agronomy
dc.contributor.department Agricultural and Biosystems Engineering
dc.date 2018-02-15T19:22:55.000
dc.date.accessioned 2020-06-29T23:04:01Z
dc.date.available 2020-06-29T23:04:01Z
dc.date.embargo 2015-01-29
dc.date.issued 2015-01-13
dc.description.abstract <p>Inclusion of perennial vegetation filter strips (PFSs) in the toeslope of annual cropland watersheds can decrease NO<sub>3</sub><sup>−</sup>–N losses to ground and surface waters. Although PFSs are similar to riparian buffers, the processes responsible for NO<sub>3</sub><sup>−</sup>–N removal from PFSs are not well understood. Our objectives were to (i) determine the importance of denitrification as a sink for NO<sub>3</sub><sup>−</sup>–N loss from PFSs and (ii) evaluate how PFSs alter the biophysical processes that affect the relative importance of N<sub>2</sub>O and N<sub>2</sub> emissions. To address our objectives, we used a coupled field laboratory approach with experimental watersheds that included the following treatments: (i) PFSs covering the bottom 10% of the watershed and an annual corn–soybean crop rotation covering the remaining upslope 90% (PFS); (ii) 100% corn–soybean rotation (CORN); and (iii) 19-yr-old 100% restored native grassland (RNG). In situ N<sub>2</sub>O flux rates and laboratory N<sub>2</sub>O/(N<sub>2</sub> + N<sub>2</sub>O) ratios were highest in CORN watersheds followed by PFS and RNG watersheds. In contrast, potentially mineralizable C and denitrification enzyme activity (DEA) were highest in PFS and RNG watersheds and lowest in CORN watersheds. Furthermore, there was a negative correlation between N<sub>2</sub>O/(N<sub>2</sub> + N<sub>2</sub>O) ratio and DEA. In the laboratory, N<sub>2</sub> fluxes were highest in PFS followed by RNG and CORN. These results indicate that PFS watersheds support greater total denitrification while emitting less N<sub>2</sub>O than croplands. Greater potentially mineralizable C in PFS and RNG suggest C availability is an important factor affecting more complete denitrification. These results suggest PFSs function similar to riparian buffers and have potential to reduce NO<sub>3</sub><sup>−</sup>–N losses from annual croplands by denitrification to N<sub>2</sub>.</p>
dc.description.comments <p>This article is from <em>Soil Science Society of America Journal</em> 79 (2015): 239–250, doi:<a href="http://dx.doi.org/10.2136/sssaj2014.05.0221" target="_blank">10.2136/sssaj2014.05.0221</a>.</p>
dc.format.mimetype application/pdf
dc.identifier archive/lib.dr.iastate.edu/agron_pubs/29/
dc.identifier.articleid 1028
dc.identifier.contextkey 6583501
dc.identifier.s3bucket isulib-bepress-aws-west
dc.identifier.submissionpath agron_pubs/29
dc.identifier.uri https://dr.lib.iastate.edu/handle/20.500.12876/4631
dc.language.iso en
dc.source.bitstream archive/lib.dr.iastate.edu/agron_pubs/29/0-2015_Iqbal_DenitrificationNitrous_Supp.pdf|||Fri Jan 14 23:12:50 UTC 2022
dc.source.bitstream archive/lib.dr.iastate.edu/agron_pubs/29/2015_Iqbal_DenitrificationNitrous.pdf|||Fri Jan 14 23:12:51 UTC 2022
dc.source.uri 10.2136/sssaj2014.05.0221
dc.subject.disciplines Agricultural Science
dc.subject.disciplines Agriculture
dc.subject.disciplines Agronomy and Crop Sciences
dc.subject.disciplines Bioresource and Agricultural Engineering
dc.subject.disciplines Water Resource Management
dc.subject.keywords Agricultural and Biosystems Engineering
dc.subject.keywords Leopold Center
dc.supplemental.bitstream 2015_Iqbal_DenitrificationNitrous_Supp.pdf
dc.title Denitrification and Nitrous Oxide Emissions in Annual Croplands, Perennial Grass Buffers, and Restored Perennial Grasslands
dc.type article
dc.type.genre article
dspace.entity.type Publication
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