{"id":{"repo_id":"lancaster","oai_identifier":"oai:eprints.lancs.ac.uk:126966"},"canonical_url":"https://search.dev.ndltd.org/etd/lancaster/oai:eprints.lancs.ac.uk:126966","repository":{"repo_id":"lancaster","name":"Lancaster University","base_url":"https://eprints.lancs.ac.uk/cgi/oai2"},"display":{"title":"Soil drying and re-wetting effects on phosphorus availability and plant yields","abstract":"Water and phosphorus (P) are essential resources for crop production, yet both are increasingly limited, threatening global food security. Soil drying and re-wetting (DRW) has reportedly increased P availability in numerous soils, whilst intermittent irrigation that applies less water than conventional full irrigation can maintain crop yields. To test the hypothesis that DRW could release P at soil water potentials (SWPs) that can support plant growth, thereby increasing crop P use efficiency and yields, experiments at different scales aimed to evaluate P release and plant uptake. Laboratory studies using three low-P UK soils determined that available P (sodium bicarbonate extractable P) significantly increased (by 4-7 mg kg-1) as SWP decreased (to a minimum of -212 MPa). A significant change point (releasing 2 mg P kg-1) occurred at -2.9 MPa. A pot study showed that surface soil drying to this change point did not increase P availability over one or two DRW cycles, suggesting laboratory results could not be scaled up spatially and temporally. Initially air-drying (to -38 MPa) and re-wetting soil prior to planting Brachypodium distachyon in pots significantly increased available P at transplanting (by 1 mg kg-1) and doubled grain yields independent of P fertiliser application. In a field trial in central Madagascar in low-P, highly P-fixing soil, applying alternate wetting and drying (AWD) or post-anthesis soil drying to Oryza sativa hardly altered P uptake or yields. Thus, DRW increased P availability and yields in pots, but plants did not benefit during a cropping cycle in the field. Applying P fertiliser (10 or 25 kg ha-1) had a greater effect than AWD, with optimal harvest index (HI) and P use efficiency (PUE) at the intermediate rate. Further research to determine locally-relevant management techniques, stimulating P release at appropriate spatial and temporal scales to allow plant uptake, is urgently required.","abstract_html":"Water and phosphorus (P) are essential resources for crop production, yet both are increasingly limited, threatening global food security. Soil drying and re-wetting (DRW) has reportedly increased P availability in numerous soils, whilst intermittent irrigation that applies less water than conventional full irrigation can maintain crop yields. To test the hypothesis that DRW could release P at soil water potentials (SWPs) that can support plant growth, thereby increasing crop P use efficiency and yields, experiments at different scales aimed to evaluate P release and plant uptake. Laboratory studies using three low-P UK soils determined that available P (sodium bicarbonate extractable P) significantly increased (by 4-7 mg kg-1) as SWP decreased (to a minimum of -212 MPa). A significant change point (releasing 2 mg P kg-1) occurred at -2.9 MPa. A pot study showed that surface soil drying to this change point did not increase P availability over one or two DRW cycles, suggesting laboratory results could not be scaled up spatially and temporally. Initially air-drying (to -38 MPa) and re-wetting soil prior to planting Brachypodium distachyon in pots significantly increased available P at transplanting (by 1 mg kg-1) and doubled grain yields independent of P fertiliser application. In a field trial in central Madagascar in low-P, highly P-fixing soil, applying alternate wetting and drying (AWD) or post-anthesis soil drying to Oryza sativa hardly altered P uptake or yields. Thus, DRW increased P availability and yields in pots, but plants did not benefit during a cropping cycle in the field. Applying P fertiliser (10 or 25 kg ha-1) had a greater effect than AWD, with optimal harvest index (HI) and P use efficiency (PUE) at the intermediate rate. Further research to determine locally-relevant management techniques, stimulating P release at appropriate spatial and temporal scales to allow plant uptake, is urgently required.","abstract_has_math":false,"creators":["Wright, Hannah","Dodd, Ian","Blackwell, Martin S. A."],"institution":"Lancaster University","degree_name":"Ph.D.","degree_level":"doctoral","degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2018,"date_issued":"2018","date_published":"2018","updated_at":"2026-07-24T02:48:45Z","subjects":[],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":null,"outbound_label":null,"outbound_source":null},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Wright, Hannah","Dodd, Ian","Blackwell, Martin S. 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Soil drying and re-wetting (DRW) has reportedly increased P availability in numerous soils, whilst intermittent irrigation that applies less water than conventional full irrigation can maintain crop yields. To test the hypothesis that DRW could release P at soil water potentials (SWPs) that can support plant growth, thereby increasing crop P use efficiency and yields, experiments at different scales aimed to evaluate P release and plant uptake. Laboratory studies using three low-P UK soils determined that available P (sodium bicarbonate extractable P) significantly increased (by 4-7 mg kg-1) as SWP decreased (to a minimum of -212 MPa). A significant change point (releasing 2 mg P kg-1) occurred at -2.9 MPa. A pot study showed that surface soil drying to this change point did not increase P availability over one or two DRW cycles, suggesting laboratory results could not be scaled up spatially and temporally. Initially air-drying (to -38 MPa) and re-wetting soil prior to planting Brachypodium distachyon in pots significantly increased available P at transplanting (by 1 mg kg-1) and doubled grain yields independent of P fertiliser application. In a field trial in central Madagascar in low-P, highly P-fixing soil, applying alternate wetting and drying (AWD) or post-anthesis soil drying to Oryza sativa hardly altered P uptake or yields. Thus, DRW increased P availability and yields in pots, but plants did not benefit during a cropping cycle in the field. Applying P fertiliser (10 or 25 kg ha-1) had a greater effect than AWD, with optimal harvest index (HI) and P use efficiency (PUE) at the intermediate rate. Further research to determine locally-relevant management techniques, stimulating P release at appropriate spatial and temporal scales to allow plant uptake, is urgently required."]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Soil drying and re-wetting effects on phosphorus availability and plant yields"]}]}],"canonical_facts":{"dc:creator":["Wright, Hannah","Dodd, Ian","Blackwell, Martin S. A."],"dc:date":["2018"],"dc:date.issued":["2018"],"dc:description.abstract":["Water and phosphorus (P) are essential resources for crop production, yet both are increasingly limited, threatening global food security. Soil drying and re-wetting (DRW) has reportedly increased P availability in numerous soils, whilst intermittent irrigation that applies less water than conventional full irrigation can maintain crop yields. To test the hypothesis that DRW could release P at soil water potentials (SWPs) that can support plant growth, thereby increasing crop P use efficiency and yields, experiments at different scales aimed to evaluate P release and plant uptake. Laboratory studies using three low-P UK soils determined that available P (sodium bicarbonate extractable P) significantly increased (by 4-7 mg kg-1) as SWP decreased (to a minimum of -212 MPa). A significant change point (releasing 2 mg P kg-1) occurred at -2.9 MPa. A pot study showed that surface soil drying to this change point did not increase P availability over one or two DRW cycles, suggesting laboratory results could not be scaled up spatially and temporally. Initially air-drying (to -38 MPa) and re-wetting soil prior to planting Brachypodium distachyon in pots significantly increased available P at transplanting (by 1 mg kg-1) and doubled grain yields independent of P fertiliser application. In a field trial in central Madagascar in low-P, highly P-fixing soil, applying alternate wetting and drying (AWD) or post-anthesis soil drying to Oryza sativa hardly altered P uptake or yields. Thus, DRW increased P availability and yields in pots, but plants did not benefit during a cropping cycle in the field. Applying P fertiliser (10 or 25 kg ha-1) had a greater effect than AWD, with optimal harvest index (HI) and P use efficiency (PUE) at the intermediate rate. Further research to determine locally-relevant management techniques, stimulating P release at appropriate spatial and temporal scales to allow plant uptake, is urgently required."],"dc:format":["application/pdf"],"dc:identifier.uri":["https://eprints.lancs.ac.uk/id/eprint/126966/1/2018wrightphd.pdf"],"dc:publisher.commercial":["Lancaster University"],"dc:publisher.department":["Lancaster Environment Centre"],"dc:publisher.institution":["Lancaster University"],"dc:relation.isreferencedby":["https://eprints.lancs.ac.uk/id/eprint/126966/"],"dc:title":["Soil drying and re-wetting effects on phosphorus availability and plant yields"],"dc:type":["Thesis"],"dc:type.qualificationlevel":["doctoral"],"dc:type.qualificationname":["Ph.D."]},"updated_at":"2026-07-24T02:48:45Z"}