How the Rhizosphere May Favor Water Availability to Roots

被引:79
作者
Carminati, Andrea [1 ]
Schneider, Christoph L.
Moradi, Ahmad B. [1 ]
Zarebanadkouki, Mohsen [2 ]
Vetterlein, Doris [2 ]
Vogel, Hans-Joerg [2 ]
Hildebrandt, Anke
Weller, Ulrich [2 ]
Schueler, Lennart [1 ]
Oswald, Sascha E. [3 ]
机构
[1] UFZ Helmholtz Ctr Environm Res, Hydrogeol Dep, Leipzig, Germany
[2] UFZ Helmholtz Ctr Environm Res, Halle, Germany
[3] Univ Potsdam, Inst Earth & Environm Sci, Potsdam, Germany
关键词
PLANT-ROOTS; SOIL-WATER; PHOSPHOLIPID SURFACTANTS; NUMERICAL-SIMULATION; HYDRAULIC-PROPERTIES; AXENIC MAIZE; EXTRACTION; INTERFACE; PROFILES; MUCILAGE;
D O I
10.2136/vzj2010.0113
中图分类号
X [环境科学、安全科学];
学科分类号
08 ; 0830 ;
摘要
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.
引用
收藏
页码:988 / 998
页数:11
相关论文
共 27 条
[1]  
[Anonymous], 1964, HYDROLOGY PAPERS COL
[2]   Dynamics of soil water content in the rhizosphere [J].
Carminati, Andrea ;
Moradi, Ahmad B. ;
Vetterlein, Doris ;
Vontobel, Peter ;
Lehmann, Eberhard ;
Weller, Ulrich ;
Vogel, Hans-Joerg ;
Oswald, Sascha E. .
PLANT AND SOIL, 2010, 332 (1-2) :163-176
[3]   When Roots Lose Contact [J].
Carminati, Andrea ;
Vetterlein, Doris ;
Weller, Ulrich ;
Vogel, Hans-Joerg ;
Oswald, Sascha E. .
VADOSE ZONE JOURNAL, 2009, 8 (03) :805-809
[4]   Diffusion of glucose in microbial extracellular polysaccharide as affected by water potential [J].
Chenu, C ;
Roberson, EB .
SOIL BIOLOGY & BIOCHEMISTRY, 1996, 28 (07) :877-884
[5]  
COWAN I. R., 1965, J APPL ECOL, V2, P221, DOI 10.2307/2401706
[6]  
De Willigen P., 1987, Roots, plant production and nutrient use efficiency
[7]   Upscaling from rhizosphere to whole root system: Modelling the effects of phospholipid surfactants on water and nutrient uptake [J].
Dunbabin, Vanessa M. ;
McDermott, Sean ;
Bengough, A. Glyn .
PLANT AND SOIL, 2006, 283 (1-2) :57-72
[8]   SIMULATION OF FIELD WATER-UPTAKE BY PLANTS USING A SOIL-WATER DEPENDENT ROOT EXTRACTION FUNCTION [J].
FEDDES, RA ;
KOWALIK, P ;
KOLINSKAMALINKA, K ;
ZARADNY, H .
JOURNAL OF HYDROLOGY, 1976, 31 (1-2) :13-26
[9]  
GARDNER W. R., 1960, SOIL SCI, V89, P63, DOI 10.1097/00010694-196002000-00001
[10]   Roots, rhizosphere and soil: the route to a better understanding of soil science? [J].
Gregory, PJ .
EUROPEAN JOURNAL OF SOIL SCIENCE, 2006, 57 (01) :2-12