Alternate wetting and drying irrigation increases water and phosphorus use efficiency independent of substrate phosphorus status of vegetative rice plants

Acosta-Motos, Jose Ramon and Rothwell, Shane and Massam, Maggie and Albacete, Alfonso and Zhang, Hao and Dodd, Ian (2020) Alternate wetting and drying irrigation increases water and phosphorus use efficiency independent of substrate phosphorus status of vegetative rice plants. Plant Physiology and Biochemistry, 155. pp. 914-926. ISSN 0981-9428

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Abstract

Sustainable approaches to rice cultivation that apply less irrigation and chemical fertilisers are required to increase crop resource use efficiency. Although alternate wetting and drying (AWD) has been widely promoted as a water-saving irrigation technique, its interactions with phosphorus (P) nutrition have attracted little attention. Vegetative rice plants were grown with two phosphorus levels, fertilised (HP) or un-fertilised (LP), and either continuous flooding (CF) or AWD irrigation. Treatment effects on substrate P bioavailability (measured by Diffusive Gradients in Thin films – DGT-P), plant and substrate water relations, and foliar phytohormone status, were assessed along with P partitioning in planta. Shoot biomass and leaf area under different irrigation treatments depended on substrate P status (significant P x irrigation interaction), since LP decreased these variables under CF, but had no significant effect on plants grown under AWD. AWD maintained DGT-P concentrations and increased maximal root length, but decreased root P concentrations and P offtake. Substrate drying decreased stomatal conductance (gs) and leaf water potential (Ψleaf) but re-flooding increased gs. AWD increased foliar abscisic acid (ABA), isopentenyl adenine (iP) and 1-aminocyclopropane-1-carboxylic acid (ACC) concentrations, but decreased trans-zeatin (tZ) and gibberellin A1 (GA1) concentrations. Low P increased ACC and jasmonic acid (JA) concentrations but decreased gibberellin A4 (GA4) concentrations. Across all treatments, stomatal conductance was negatively correlated with foliar ABA concentration but positively correlated with GA1 concentration. Changes in shoot phytohormone concentrations were associated with increased water and phosphorus use efficiency (WUE and PUE) of vegetative rice plants grown under AWD.

Item Type:
Journal Article
Journal or Publication Title:
Plant Physiology and Biochemistry
Additional Information:
This is the author’s version of a work that was accepted for publication in Plant Physiology and Biochemistry. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Plant Physiology and Biochemistry, 155, 2020 DOI: 10.1016/j.plaphy.2020.06.017
Uncontrolled Keywords:
/dk/atira/pure/subjectarea/asjc/1300/1314
Subjects:
ID Code:
146647
Deposited By:
Deposited On:
18 Aug 2020 11:10
Refereed?:
Yes
Published?:
Published
Last Modified:
22 Sep 2020 05:10