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dc.contributor.authorCook, FJ
dc.contributor.authorKnight, JH
dc.contributor.authorKelliher, FM
dc.date.accessioned2017-05-03T14:40:46Z
dc.date.available2017-05-03T14:40:46Z
dc.date.issued2013
dc.date.modified2014-06-18T05:54:53Z
dc.identifier.issn1838-675X
dc.identifier.doi10.1071/SR13223
dc.identifier.urihttp://hdl.handle.net/10072/60506
dc.description.abstractA set of equations governing oxygen diffusion and consumption in soils has been developed to include microbial and plant-root sinks. The dependent variable is the transformed oxygen concentration, which is the difference between the gaseous concentration and a scaled value of the aqueous oxygen concentration at the root-soil interface. The results show how, as the air-filled porosity decreases, the reduced oxygen flux causes the depth of extinction to decrease. The results also show how the depth of extinction at a particular value of soil water content decreases with increasing temperature, due to increased microbial respiration. The critical value of water content at which the oxygen concentration goes to extinction at a finite depth was compared with alternative calculations with only a microbial sink. By ignoring the feedback of oxygen concentration on root uptake, the alternative calculations yielded substantially higher critical values of water content at all temperatures. Two soil oxygen diffusion coefficient functions from the literature were compared and shown to give significantly different critical values of water content for fine-textured soils, one more realistic than the other. A single relationship between the extinction depth and the ratio of the water content to the critical value was shown to apply for all temperatures and soil textures. The oxygen profiles were used along with a function relating redox potential to oxygen concentration to generate redox potential profiles. This application of the model could be useful in explaining soil biochemical processes in soils. For one such process, denitrification, the depth at which a critical oxygen concentration is reached was calculated as a function of the air-filled porosity and temperature of the soil. The implications of the critical value of soil water content in terms of water-filled pore space and matric potential are discussed in relation to the diffusion coefficient functions and recent literature.
dc.description.peerreviewedYes
dc.description.publicationstatusYes
dc.languageEnglish
dc.language.isoeng
dc.publisherC S I R O Publishing
dc.publisher.placeAustralia
dc.relation.ispartofstudentpublicationN
dc.relation.ispartofpagefrom539
dc.relation.ispartofpageto553
dc.relation.ispartofissue6
dc.relation.ispartofjournalSoil Research
dc.relation.ispartofvolume51
dc.rights.retentionY
dc.subject.fieldofresearchOther environmental sciences not elsewhere classified
dc.subject.fieldofresearchcode419999
dc.titleModelling oxygen transport in soil with plant root and microbial oxygen consumption: depth of oxygen penetration
dc.typeJournal article
dc.type.descriptionC1 - Articles
dc.type.codeC - Journal Articles
gro.facultyGriffith Sciences, Griffith School of Environment
gro.hasfulltextNo Full Text
gro.griffith.authorCook, Freeman J.


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