Bare Soil Carbon Dioxide Fluxes with Time and Depth Determined by High-Resolution Gradient-Based Measurements and Surface Chambers Xiao, X. Kuang, X. Horton, Robert Sauer, T. J. Heitman, J. L. Horton, R.
dc.contributor.department Agronomy 2018-01-31T18:13:31.000 2020-06-29T23:05:09Z 2020-06-29T23:05:09Z 2015-01-01
dc.description.abstract <p>Soil CO<sub>2</sub> production rates and fluxes vary with time and depth. The shallow near-surface soil layer is important for myriad soil processes, yet knowledge of dynamic CO<sub>2</sub> concentrations and fluxes in this complex zone is limited. We used a concentration gradient method (CGM) to determine CO<sub>2</sub> production and effluxes with depth in shallow layers of a bare soil. The CO<sub>2</sub>concentration was continuously measured at 13 depths in the 0- to 200-mm soil layer. For an 11-d period, 2% of the soil CO<sub>2</sub> was produced below a depth of 175 mm, 8% was produced in the 50- to 175-mm soil layer, and 90% was produced in the 0- to 50-mm soil layer. Soil CO<sub>2</sub>concentration showed similar diurnal patterns with temperature in deeper soil layers and out-of-phase diurnal patterns in surface soil layers. Soil CO<sub>2</sub> flux from most of the soil layers can be described by an exponential function of soil temperature, with temperature sensitivity (<em>Q</em><sub>10</sub>) ranging from 1.40 to 2.00 (1.62 ± 0.17). The temperature-normalized CO<sub>2</sub> fluxes are related to soil water content with a positive linear relationship in surface soil layers and a negative relationship in deep soil layers. The CO<sub>2</sub> fluxes from CGM and chamber methods had good agreement at multiple time scales, which showed that the CGM method was able to estimate near-surface soil CO<sub>2</sub> fluxes and production. The contrasting patterns between surface and deep layers of soil CO<sub>2</sub> concentration and fluxes suggest the necessity of intensive CO<sub>2</sub>concentration measurements in the surface soil layer for accurate determination of soil-atmosphere CO<sub>2</sub> flux when using the CGM.</p>
dc.description.comments <p>This article is published as Xiao, Xinhua, X. Kuang, T. J. Sauer, J. L. Heitman, and R. Horton. "Bare soil carbon dioxide fluxes with time and depth determined by high-resolution gradient-based measurements and surface chambers." <em>Soil Science Society of America Journal</em> 79, no. 4 (2015): 1073-1083. doi: <a href="" target="_blank">10.2136/sssaj2015.02.0079</a>. </p>
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dc.identifier archive/
dc.identifier.articleid 1480
dc.identifier.contextkey 11454119
dc.identifier.s3bucket isulib-bepress-aws-west
dc.identifier.submissionpath agron_pubs/428
dc.language.iso en
dc.source.bitstream archive/|||Sat Jan 15 00:14:12 UTC 2022
dc.source.uri 10.2136/sssaj2015.02.0079
dc.subject.disciplines Agriculture
dc.subject.disciplines Hydrology
dc.subject.disciplines Soil Science
dc.title Bare Soil Carbon Dioxide Fluxes with Time and Depth Determined by High-Resolution Gradient-Based Measurements and Surface Chambers
dc.type article
dc.type.genre article
dspace.entity.type Publication
relation.isAuthorOfPublication d3fb0917-6868-417e-9695-a010896cfafa
relation.isOrgUnitOfPublication fdd5c06c-bdbe-469c-a38e-51e664fece7a
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