Root growth pressure at the soil–root interface

Misra, R. K. (2003) Root growth pressure at the soil–root interface. In: Encyclopedia of soil science, 2nd ed. Marcel Dekker, Inc., New York, NY. United States, pp. 1-3. ISBN 978-0-8493-3830-4


Plant roots apply force to make cylindrical cavities in soil, which allow them to grow and elongate. However, in certain situations, roots need to apply only a small amount of force, for instance, when a root tip reaches an existing channel (made by either earthworms, roots of a previous crop, or cracks from shrinkage of soil). Studies in homogeneous soils of uniform strength usually show development of localized zones of compressed soil around roots.

A root growing in soil exerts force within the zone of elongation behind the root cap (Fig. 1) until the elongation zone reaches maturity and the force shifts to a new elongation zone developed through cell division. Roots apply force in axial and radial directions. As roots have a cylindrical shape (some departure from cylindrical shape is expected for roots in very strong soils) they apply force over a cylindrical area. Therefore, root growth pressure is an estimated quantity from separate measurements of force and area. For axial pressure, area over which the force is exerted is circular, which can be estimated from the measurement of diameter in the elongation zone of the root. For radial pressure, force is exerted over a cylindrical surface; so, both diameter and length of the root are important. At the soil-root interface, axial and radial root growth forces are expected to vary with time, and so does the area over which these forces are exerted.

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Item Type: Book Chapter (Commonwealth Reporting Category B)
Refereed: Yes
Item Status: Live Archive
Additional Information: ©2003 Marcel Dekker, Inc. All rights reserved.
Faculty / Department / School: Historic - Faculty of Engineering and Surveying - Department of Agricultural, Civil and Environmental Engineering
Date Deposited: 06 Oct 2010 03:47
Last Modified: 11 Nov 2013 06:10
Uncontrolled Keywords: radial pressure; axial pressure
Fields of Research : 06 Biological Sciences > 0607 Plant Biology > 060705 Plant Physiology
05 Environmental Sciences > 0503 Soil Sciences > 050305 Soil Physics
05 Environmental Sciences > 0503 Soil Sciences > 050399 Soil Sciences not elsewhere classified
Socio-Economic Objective: D Environment > 96 Environment > 9614 Soils > 961499 Soils not elsewhere classified
Identification Number or DOI: 10.1081/E-ESS-120014315

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