Root–soil friction: quantification provides evidence for measurable benefits for manipulation of root-tip traits

Blair M. McKenzie, Christopher E. Mullins, Judith M. Tisdall, A. Glyn Bengough

    Research output: Contribution to journalArticle

    16 Citations (Scopus)

    Abstract

    To penetrate soil, a root requires pressure both to expand the cavity it is to occupy, sn, and to overcome root–soil friction, sf. Difficulties in estimating these two pressures independently have limited our ability to estimate the coefficient of soil–root friction, µsr. We used a rotated penetrometer probe, of similar dimensions to a root, and for the first time entering the soil at a similar rate to a root tip, to estimate sn. Separately we measured root penetration resistance (PR) Qr. Root PR was between two to four times sn. We estimated that the coefficient of root–soil friction (µsr) was 0.21–0.26, based on the geometry of the root tip. This is slightly larger than the 0.05–0.15 characteristic of boundary lubricants. Scanning electron microscopy showed that turgid border cells lined the root channel, supporting our hypothesis that the lubricant consisted of mucilage sandwiched between border cells and the surface of the root cap and epidermis. This cell–cell lubrication greatly decreased the friction that would otherwise be experienced had the surface of the root proper slid directly past unlubricated soil particles. Because root–soil friction can be a substantial component of root PR, successful manipulation of friction represents a promising opportunity for improving plant performance.
    Original languageEnglish
    Pages (from-to)1085-1092
    Number of pages8
    JournalPlant, Cell & Environment
    Volume36
    Issue number6
    DOIs
    Publication statusPublished - Jun 2013

    Keywords

    • bulk density
    • COMPACTION
    • Lubrication
    • MECHANICAL IMPEDANCE
    • rhizosphere
    • soil strength

    Fingerprint Dive into the research topics of 'Root–soil friction: quantification provides evidence for measurable benefits for manipulation of root-tip traits'. Together they form a unique fingerprint.

  • Cite this