Plant and Soil

, Volume 97, Issue 3, pp 333–344 | Cite as

Rates of rhizodeposition and ammonium depletion in the rhizosphere of axenic oat roots

  • J. A. Trofymow
  • D. C. Coleman
  • C. Cambardella
Article

Summary

A multiple split root chamber and artificial soil were developed which allowed for maintenance of axenic conditions and for the isolation of soil from specific regions of single roots. A sterile minirhizotron was used to measure patterns and rates of root extension under sterile conditions. Carbon and nitrogen distributions in the rhizosphere of sterile oat roots were measured in combination with rates of root elongation to calculate specific rates of rhizodeposition and ammonium nitrogen uptake. The highest rates of rhizodeposition C production and N depletion occurred at the root tip (first day segment). Rhizodeposited soluble and insoluble C compounds represented up to 50% of the standing root biomass C. Within 48 hours after root entry, levels of rhizosphere ammonium-N decreased by 40–50%. The results were summarized in a simple model of root growth, rhizodeposition, and NH 4 + −H uptake.

Key words

Artificial soil Axenic roots Oats Rhizosphere dynamics 

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Copyright information

© Martinus Nijhoff Publishers 1987

Authors and Affiliations

  • J. A. Trofymow
    • 1
  • D. C. Coleman
    • 1
  • C. Cambardella
    • 1
  1. 1.Natural Resource Ecology LaboratoryColorado State UniversityFort CollinsUSA

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