Details zur Publikation

Kategorie Textpublikation
Referenztyp Zeitschriften
DOI 10.2136/vzj2010.0113
Titel (primär) How the rhizosphere may favor water availability to roots
Autor Carminati, A.; Schneider, C.L.; Moradi, A.B.; Zarebanadkouki, M.; Vetterlein, D.; Vogel, H.-J.; Hildebrandt, A.; Weller, U.; Schüler, L.; Oswald, S.E.
Quelle Vadose Zone Journal
Erscheinungsjahr 2011
Department CHS; HDG; BOPHY
Band/Volume 10
Heft 3
Seite von 988
Seite bis 998
Sprache englisch
Abstract

Recent studies have shown that rhizosphere hydraulic properties may differ from those of the bulk soil. Specifically, mucilage at the root–soil interface may increase the rhizosphere water holding capacity and hydraulic conductivity during drying. The goal of this study was to point out the implications of such altered rhizosphere hydraulic properties for soil–plant water relations. We addressed this problem through modeling based on a steady-rate approach. We calculated the water flow toward a single root assuming that the rhizosphere and bulk soil were two concentric cylinders having different hydraulic properties. Based on our previous experimental results, we assumed that the rhizosphere had higher water holding capacity and unsaturated conductivity than the bulk soil. The results showed that the water potential gradients in the rhizosphere were much smaller than in the bulk soil. The consequence is that the rhizosphere attenuated and delayed the drop in water potential in the vicinity of the root surface when the soil dried. This led to increased water availability to plants, as well as to higher effective conductivity under unsaturated conditions. The reasons were two: (i) thanks to the high unsaturated conductivity of the rhizosphere, the radius of water uptake was extended from the root to the rhizosphere surface; and (ii) thanks to the high soil water capacity of the rhizosphere, the water depletion in the bulk soil was compensated by water depletion in the rhizosphere. We conclude that under the assumed conditions, the rhizosphere works as an optimal hydraulic conductor and as a reservoir of water that can be taken up when water in the bulk soil becomes limiting.
dauerhafte UFZ-Verlinkung https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=11198
Carminati, A., Schneider, C.L., Moradi, A.B., Zarebanadkouki, M., Vetterlein, D., Vogel, H.-J., Hildebrandt, A., Weller, U., Schüler, L., Oswald, S.E. (2011):
How the rhizosphere may favor water availability to roots
Vadose Zone J. 10 (3), 988 - 998 10.2136/vzj2010.0113