The Mathematical Institute, University of Oxford, Eprints Archive

A dual porosity model of nutrient uptake by root hairs soil

Zygalakis, K. C. and Kirk, G. J. D. and Jones, D. L. and Wissuwa, M. and Roose, T. (2010) A dual porosity model of nutrient uptake by root hairs soil. New Phytologist . (Submitted)

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Abstract

The importance of root hairs in uptake of sparingly-soluble nutrients is understood qualitatively, but not quantitatively, and this limits efforts to breed plants tolerant of nutrient-deficient soils.

We develop a mathematical model of nutrient uptake by root hairs allowing for hair geometry and the details of nutrient transport to hairs through soil, including diffusion within and between soil particles.

Compared with conventional ‘single porosity’ models, this ‘dual porosity’ model predicts greater root uptake because more nutrient is available by slow release from within the soil particles. Also the effect of soil moisture is less important with the dual porosity model because the effective volume available for diffusion within the soil is larger, and the predicted effects of hair length and density are different.

Consistent with experimental observations, increases in hair length give greater increases in uptake than increases in hair density per unit main root length. The effect of hair density is less in dry soil because the minimum concentration in solution in the hair zone for net influx is reached more rapidly. The effect of hair length is much less sensitive to soil moisture.

Implications for manipulation of root architecture through plant breeding are discussed.

Item Type:Article
Subjects:D - G > General
Research Groups:Oxford Centre for Collaborative Applied Mathematics
ID Code:1040
Deposited By:Peter Hudston
Deposited On:07 Jan 2011 08:43
Last Modified:09 Feb 2012 15:48

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