TY - JOUR

T1 - A dual porosity model of nutrient uptake by root hairs

AU - Zygalakis, K. C.

AU - Kirk, G. J. D.

AU - Jones, D. L.

AU - Wissuwa, M.

AU - Roose, T.

PY - 2011/11

Y1 - 2011/11

N2 - The importance of root hairs in the uptake of sparingly soluble nutrients is understood qualitatively, but not quantitatively, and this limits efforts to breed plants tolerant of nutrient-deficient soils.Here, we develop a mathematical model of nutrient uptake by root hairs allowing for hair geometry and the details of nutrient transport through soil, including diffusion within and between soil particles. We give illustrative results for phosphate uptake.Compared with conventional ‘single porosity’ models, this ‘dual porosity’ model predicts greater root uptake because more nutrient is available by slow release from within soil particles. Also the effect of soil moisture is less important with the dual porosity model because the effective volume available for diffusion in the soil is larger, and the predicted effects of hair length and density are different.Consistent with experimental observations, with the dual porosity model, 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 for net influx is reached more rapidly. The effect of hair length is much less sensitive to soil moisture.

AB - The importance of root hairs in the uptake of sparingly soluble nutrients is understood qualitatively, but not quantitatively, and this limits efforts to breed plants tolerant of nutrient-deficient soils.Here, we develop a mathematical model of nutrient uptake by root hairs allowing for hair geometry and the details of nutrient transport through soil, including diffusion within and between soil particles. We give illustrative results for phosphate uptake.Compared with conventional ‘single porosity’ models, this ‘dual porosity’ model predicts greater root uptake because more nutrient is available by slow release from within soil particles. Also the effect of soil moisture is less important with the dual porosity model because the effective volume available for diffusion in the soil is larger, and the predicted effects of hair length and density are different.Consistent with experimental observations, with the dual porosity model, 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 for net influx is reached more rapidly. The effect of hair length is much less sensitive to soil moisture.

KW - mathematical model

KW - nutrient uptake

KW - phosphate

KW - rhizosphere

KW - root hairs

U2 - 10.1111/j.1469-8137.2011.03840.x

DO - 10.1111/j.1469-8137.2011.03840.x

M3 - Article

VL - 192

SP - 676

EP - 688

JO - New Phytologist

JF - New Phytologist

SN - 0028-646X

IS - 3

ER -