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Root: soil adhesion in the maize rhizosphere: the rheological approach

Root: soil adhesion in the maize rhizosphere: the rheological approach

Authors :
Hiller, S.
Dexter, A. R.
Czarnes, S.
Hallett, P. D.
Bartoli, F.
Source :
Plant & Soil; 1999, Vol. 211 Issue 1, p69, 0p
Publication Year :
1999

Abstract

This study was designed to investigate the strength of attachment ofplant seedling roots to the soil in which they were grown. The studyalso assessed the effects of differing soil textures and differing soil matric potentials upon the strength of the root:soil attachment. A device for growing roots upon a soil surface was designed, and was used to produce roots which were attached to the soil. In order to quantify root:soil adhesion, roots of maize seedlings, grown on the soil surface, were subsequently peeled off using a universal test machine, in conjunction with simultaneous time-lapse video observation. To clarify the partitioning of energy in the root:soil peeling test, separate mechanical tests on roots, and on two adherent remoulded topsoil balls were also carried out. The seedling root was characterised bya low bending stiffness. The energy stored in bending was negligible, compared to the root:soil adhesion energy. The mechanical properties of two adherent remoulded topsoil balls were a decrease of the soil:soil adhesion energy as the soil:soil plastic energy increased. These two parameters were therefore interdependent. Using a video-camera system, it was possible to separate the different processes occurringduring the root:soil peeling test, in particular, the seed:soil adhesion and the root:soil soil adhesion. An interpretation of the complex and variable force:displacement curves was thus possible, enabling calculation of the root:soil interfacial rupture energy. At a given suction (10 kPa), the results of the peeling test showed a clear soil texture effect on the value of the root:soil interfacial rupture energy. In contrast, for the same silty topsoil, the effect of the soil water suction on the value of the interfacial rupture energy was very moderate. The root:soil interfacial rupture energy was controlled mainly by a product of microscopic soil specific surface area and the macroscopic contact surface area between the root and the soil. Biological [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
0032079X
Volume :
211
Issue :
1
Database :
Complementary Index
Journal :
Plant & Soil
Publication Type :
Academic Journal
Accession number :
8458097