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dc.contributor.authorCarmona, Carmen Rosa
dc.contributor.authorClough, Timothy J.
dc.contributor.authorMcNally, S. R.
dc.contributor.authorBeare, M. H.
dc.contributor.authorTregurtha, C. S.
dc.contributor.authorHunt, J. E.
dc.date.accessioned2020-04-30T06:17:39Z
dc.date.available2020-02-12en
dc.date.issued2020-04
dc.date.submitted2020-02-05en
dc.identifier.issn0038-0717en
dc.identifier.urihttps://hdl.handle.net/10182/11796
dc.description.abstractLong-term irrigation of temperate pastures has been reported to either increase or decrease soil organic carbon (SOC) stocks when compared with dryland systems. Understanding the short-term effects of irrigation on the fixation and partitioning of carbon (C) to plant and soil components may be important to explaining the observed differences. Continuous ¹³CO₂ pulse labelling of ryegrass (Lolium perenne L.) and white clover (Trifolium repens L.) planted mesocosms was used to quantify the net accumulation and partitioning of new photosynthate C to above- and below-ground components of the plant-soil system, including soil particle size fractions: > 250 μm, 53–250 μm, 20–53 μm, 5–20 μm and <5 μm, under simulated irrigation and dryland conditions. After the ¹³CO₂ labelling, irrigation increased the quantity of ¹³C partitioned into herbage by 16%, while reducing the quantity partitioned into roots in the 15–25 cm soil depth by 35%. However, less new photosynthate C was observed in rhizosphere soil (0–15 cm depth), while more new photosynthate C was partitioned into the 53–250 μm and <5 μm soil fractions under irrigation. Despite these differences, the net amount of new photosynthate C in the whole soil (0–25 cm depth) was similar between treatments (2511 kg new C ha⁻¹ dryland and 2509 kg new C ha⁻¹ irrigated). Therefore, irrigation did not increase the net amount of new photosynthate C in the soil despite increased above-ground pasture productivity. Based on our results, we hypothesise that the recently reported losses of SOC from irrigated pastures may be driven by faster turnover of root-derived C, which may explain the increase in photosynthate C in the fine POM soil size fraction (53–250 μm), rather than a reduction in photosynthate C inputs to the soil.en
dc.format.extent11en
dc.language.isoen
dc.publisherElsevier
dc.relationThe original publication is available from - Elsevier - https://doi.org/10.1016/j.soilbio.2020.107751en
dc.relation.urihttps://doi.org/10.1016/j.soilbio.2020.107751en
dc.rights© 2020 Elsevier Ltd. All rights reserved.
dc.subjectirrigationen
dc.subjectpastureen
dc.subjectphotosynthate carbonen
dc.subjectsoil carbonen
dc.subjectAgronomy & Agricultureen
dc.titleSeasonal irrigation affects the partitioning of new photosynthate carbon in soilen
dc.typeJournal Article
lu.contributor.unitLincoln University
lu.contributor.unitFaculty of Agriculture and Life Sciences
lu.contributor.unitDepartment of Soil and Physical Sciences
dc.identifier.doi10.1016/j.soilbio.2020.107751en
dc.relation.isPartOfSoil Biology and Biochemistryen
pubs.notesArticle number 107751en
pubs.organisational-group/LU
pubs.organisational-group/LU/Agriculture and Life Sciences
pubs.organisational-group/LU/Agriculture and Life Sciences/SOILS
pubs.organisational-group/LU/Research Management Office
pubs.organisational-group/LU/Research Management Office/QE18
pubs.publication-statusPublisheden
pubs.volume143en
lu.identifier.orcid0000-0002-5978-5274


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