A laboratory device for continual measurement of water retention and shrink/swell properties during drying/wetting cycles

Qi, Guifang (Agrocampus Ouest, Centre d'Angers, Unité de Recherche EPHOR, Environnement Physique de la plante Horticole, Angers, France) ; Michel, Jean-Charles (Agrocampus Ouest, Centre d'Angers, Unité de Recherche EPHOR, Environnement Physique de la plante Horticole, Angers, France) ; Boivin, Pascal (School of Engineering, Architecture and Landscape (hepia), HES-SO // University of Applied Sciences Western Switzerland) ; Charpentier, Sophie (Agrocampus Ozuest, Centre d'Angers, Unité de Recherche EPHOR, Environnement Physique de la plante Horticole, Angers, France)

The precise measurement of the water retention and shrink/swell properties of growing media or soil over time is important for the effective management of irrigation and fertilization. A new apparatus was developed for simultaneously and continuously measuring the water retention and shrink/swell properties of growing media during several drying/wetting cycles with varying intensities (0↔–5 kPa, 0↔–10 kPa, 0↔–32 kPa). The measurements on slightly decomposed Sphagnum peat showed encouraging results. Regardless of the intensity of drying, water retention and shrink/swell properties are mainly modified after the first drying process, resulting in degradation of density and water retention, whereas these properties are unaffected by the other cycles, even if hysteresis phenomena are always shown to take place. Variations in drying intensity reveal different physical behaviors with an inflection point observed (i.e., a change in physical behavior) for the shrink/swell and water retention curves for the highest intensity tested (from –20 kPa).


Keywords:
Article Type:
scientifique
Faculty:
Ingénierie et Architecture
School:
HEPIA - Genève
Institute:
inTNE - Institut Terre-Nature-Environnement
Date:
2011-09
Pagination:
5 p.
Published in:
HortScience
Numeration (vol. no.):
2011, vol. 46, no. 9, pp. 12978-1302
DOI:
ISSN:
0018-5345
Appears in Collection:



 Record created 2020-08-14, last modified 2020-10-27

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