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Water Relations of Winter Wheat: the Root System, Petiolar Resistance and Development of a Root Abstraction Equation

Published online by Cambridge University Press:  03 October 2008

M. McGowan
Affiliation:
Nottingham University, School of Agriculture, Sutton Bonington, Loughborough, Leicestershire, LE12 5RD, England
E. Tzimas
Affiliation:
Nottingham University, School of Agriculture, Sutton Bonington, Loughborough, Leicestershire, LE12 5RD, England

Summary

The vertical distribution of water potentials within the leaf canopy, along the stem and within the soil profile of a winter wheat crop was analysed and it is concluded the failure by previous workers to recognize the significance of petiolar resistance has probably resulted in over-estimates of the resistance of the soil to water uptake by root systems of field crops.

From an analysis of the water relations of several winter wheat crops an equation is developed to describe the extraction of soil water reserves by crop root systems, based upon values of soil water potential, root xylem potential and ‘effective’ resistance to water uptake which can be obtained from field experiments. The equation provides an empirical basis to specify the minimum desirable root system for efficient capture of soil water reserves, to analyse the effects of differing root distributions and thus to help identify situations where it would be profitable to modify rooting either by tillage or by plant breeding.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1985

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References

REFERENCES

Black, C. R. (1979). A quantitative study of the resistances to the transpirational water movement in sunflower. Journal of Experimental Botany 30:947953.CrossRefGoogle Scholar
Burch, G. J. (1979). Soil and plant resistances to water adsorption by plant roots. Australian Journal of Agricultural Research 30:279292.CrossRefGoogle Scholar
Cowan, I. R. (1965). Transport of water in the soil-plant-atmosphere system. Journal of Applied Ecology 2:221239.CrossRefGoogle Scholar
Denmead, O. T. & Millar, B. D. (1976). Water transport in wheat plants in the field. Agronomy Journal 68:297303.CrossRefGoogle Scholar
Gardner, W. R. (1960). Dynamic aspects of water availability to plants. Soil Science 89:6373.CrossRefGoogle Scholar
Gregory, P. J., McGowan, M., Biscoe, P. V. & Hunter, B. (1978a). Water relations of winter wheat (1) Growth of the root system. Journal of Agricultural Science, Cambridge 91:91102.CrossRefGoogle Scholar
Gregory, P. J., McGowan, M. & Biscoe, P. V. (1978b). Water relations of winter wheat (2) Soil water relations. Journal of Agricultural Science, Cambridge 91:102116.Google Scholar
Hillel, D. (1980). Fundamentals of Soil Physics. New York: Academic Press.Google Scholar
Jarvis, P. J. (1975). Water transfer in plants. In Heat and Mass Transfer in the Biosphere, 369394 (Eds de Vries, D. A. and Afgan, N. H.). New York: Halsted Press.Google Scholar
Kandiko, R. A., Timmis, R. & Worrall, J. (1980). Pressure volume curves of shoots and roots of normal and drought conditioned Western hemlock seedlings. Canadian Journal Forestry Research 10:1016.CrossRefGoogle Scholar
MAFF (1967). Potential Transpiration. Technical Bulletin, No. 16. London: HMSO.Google Scholar
McGowan, M., Blanch, P., Gregory, P. J. & Haycock, D. (1984). Water relations of winter wheat. 5. The root system and osmotic adjustment in relation to crop evaporation. Journal of Agricultural Science, Cambridge 102:415425.CrossRefGoogle Scholar
Newman, E. I. (1969). Resistance to water flow in soil and plant. II. A review of experimental evidence on the rhizosphere resistance. Journal of Applied Ecology 6:261272.CrossRefGoogle Scholar
Newman, E. I. (1974). Root-soil water relations. In The Plant Root and its Environment, 363440 (Ed. Carson, E. W.). Charlottesville: The University Press of Virginia.Google Scholar
Passioura, J. B. (1972). The effect of root geometry on the yield of wheat growing on stored water. Australian Journal of Agricultural Research 23:745752.CrossRefGoogle Scholar
Reicosky, D. C. & Ritchie, J. T. (1976). Relative importance of soil resistance and plant resistance in root water adsorption. Soil Science Society American Journal 40:293297.CrossRefGoogle Scholar
Slayter, R. O. (1967). Plant-water Relationships. London: Academic Press.Google Scholar
Taylor, H. M. & Klepper, B. (1976). Water uptake by cotton root systems. An examination of assumptions in the single root model. Soil Science 120:5767.CrossRefGoogle Scholar
Taylor, H. M. & Klepper, B. (1978). The role of rooting characteristics in the supply of water to plants. Advances in Agronomy 30:99128.CrossRefGoogle Scholar
Wallace, J. S. (1978). Water transpiration and leaf water relations in winter wheat crops. PhD thesis, University of Nottingham.Google Scholar
Wallace, J. S., Clark, J. A. & McGowan, M. (1983). Water relations of winter wheat (3) Components of leaf water potential and soil-plant water potential gradients. Journal of Agricultural Science, Cambridge 100:581589.CrossRefGoogle Scholar