Oxygen Diffusion in the Soil-Plant System VI. A Synopsis with Commentary1
- R. J. Luxmoore and
- L. H. Stolzy2
Three types of oxygen concentration profile within roots are described and related to conditions associated with these profiles. It is apparent that oxygen from soil aeration may be redistributed longitudinally toward the shoot or to the root tip in some situations.
The root respiratory properties and temperature influenced oxygen relations chiefly by effects on oxygen sink strength. Water film thickness around the root and root permeability to oxygen are additive resistances in the radial diffusion pathway, and as water film thickness decreased, root permeability had a more significant effect on oxygen relations. Roots with higher porosity had a higher oxygen concentration within the root and at the root tip and were less dependent on soil aeration. Potentially, modification of porosity may be a key factor in the design of root systems with high adaptability to a wide range of soil environmental conditions.
A model of root tip oxygen relations would be useful in giving a respiratory (energy) basis for relating root system development and root tip functions (cell division, elongation, salt uptake, and rhizosphere relations) to environmental factors.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.