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Increased availability of phosphorus after drying and rewetting of a grassland soil: processes and plant use

Bünemann, E. ; Keller, B. ; Hoop, D. ; Jud, K. ; Boivin, P. ; Frossard, E.

In: Plant and Soil, 2013, vol. 370, no. 1-2, p. 511-526

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    Title
    • Increased availability of phosphorus after drying and rewetting of a grassland soil: processes and plant use
    Author
    • Bünemann, E.. Institute of Agricultural Sciences, Swiss Federal Institute of Technology Zurich (ETH), Eschikon 33, 8315, Lindau, Switzerland
    • Keller, B.. Institute of Agricultural Sciences, Swiss Federal Institute of Technology Zurich (ETH), Eschikon 33, 8315, Lindau, Switzerland
    • Hoop, D.. Institute of Agricultural Sciences, Swiss Federal Institute of Technology Zurich (ETH), Eschikon 33, 8315, Lindau, Switzerland
    • Jud, K.. Institute of Agricultural Sciences, Swiss Federal Institute of Technology Zurich (ETH), Eschikon 33, 8315, Lindau, Switzerland
    • Boivin, P.. University of Applied Sciences of Western Switzerland (HES-SO), hepia Agronomy, 150 route de Presinge, Jussy, 1254, Geneva, Switzerland
    • Frossard, E.. Institute of Agricultural Sciences, Swiss Federal Institute of Technology Zurich (ETH), Eschikon 33, 8315, Lindau, Switzerland
    Document Type
    • Postprint
    OAI-PMH Identifier
    • oai:doc.rero.ch:312959
    Summary
    Aims: Drying and rewetting (DRW) often increases soil phosphorus (P) availability. Our aims were to elucidate underlying processes and assess potential plant uptake of released P. Methods: Using a grassland soil with low available and high microbial P as a model, we studied the contributions of microbial and physicochemical processes to P release by determining DRW effects on i) C:P ratios of nutrient pulses in fresh and sterilized soils, ii) aggregate stability and iii) P forms released upon soil dispersion. Use of the P pulse by maize was examined in a bioassay and a split-root experiment. Results: The strong P pulse after DRW was larger than that observed for C. Experiments with sterilized soil pointed to a non-microbial contribution to the pulse for P, but not for C. Aggregate disruption after DRW occurred due to slaking, and this released molybdate-reactive and -unreactive P. Maize benefitted from the P pulse only in the bioassay, i.e. when planted after the DRW cycle. Conclusions: The majority of C and P released upon DRW originated from the microbial biomass, but for P release, physicochemical processes were also important. In the field, the released P would only be available to drought-resistant plants