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

Boivin, Pascal (School of Engineering, Architecture and Landscape (hepia), HES-SO // University of Applied Sciences Western Switzerland) ; Bünenmann, E. K. (Institute of Agricultural Sciences, Swiss Federal Isntute of Technology, Zurich (ETH), Lindau, Switzerland) ; Keller, B. (Institute of Agricultural Sciences, Swiss Federal Isntute of Technology, Zurich (ETH), Lindau, Switzerland) ; Hoop, D. (Institute of Agricultural Sciences, Swiss Federal Isntute of Technology, Zurich (ETH), Lindau, Switzerland) ; Jud, K. (Institute of Agricultural Sciences, Swiss Federal Isntute of Technology, Zurich (ETH), Lindau, Switzerland) ; Frossard, E. (Institute of Agricultural Sciences, Swiss Federal Isntute of Technology, Zurich (ETH), Lindau, Switzerland)

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.


Article Type:
scientifique
Faculty:
Ingénierie et Architecture
School:
HEPIA - Genève
Institute:
inTNE - Institut Terre-Nature-Environnement
Date:
2013-02
Pagination:
16 p.
Published in:
Plant and Soil
Numeration (vol. no.):
2013, vol. 370, pp. 511-526
DOI:
ISSN:
0032-079X
Appears in Collection:

Note: The status of this file is: restricted


 Record created 2020-08-13, last modified 2020-10-27

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