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The phosphorus requirement of lettuce: II. A dynamic model of phosphorus uptake and growth

Published online by Cambridge University Press:  27 March 2009

M. A. Scaife
Affiliation:
National Vegetable Research Station, Wellesbourne, Warwickshire
R. Smith
Affiliation:
National Vegetable Research Station, Wellesbourne, Warwickshire

Summary

A dynamic model is presented in which the problem of predicting P response is broken down into various components, such as:

(a) Weight and P content of emerging seedling.

(b) Normal growth curve of the fully nourished plant.

(c) A ‘deficiency-tolerance’ factor relating depression of relative growth rate to plant P concentration.

(d) An ‘affinity’ term relating sink concentration to P status of plant.

(e) A perirhizal resistance term for diffusive transport to roots.

(f) Capacity and intensity of P supply from the soil. Mass flow supply via the transpiration stream is also included.

By changing parameter values one may attempt to simulate the effect of any of these factors on the shape of the P response curve and any other part of the system throughout crop life. At present the model over-estimates growth at low levels of P supply, but predicted plant P concentrations agree reasonably well with observed data.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1973

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References

Asher, C. J. & Loneragan, J. F. (1967). Response of plants to phosphate concentration in solution culture: I. Growth and P content. Soil Sci. 103, 225–33.Google Scholar
Barber, S. A. (1962). A diffusion and mass-flow concept of nutrient availability. Soil Sci. 93, 3949.Google Scholar
Dyson, P. W. & Watson, D. J. (1971). An analysis of the effects of nutrient supply on the growth of potato crops. Ann. appl. Biol. 69, 4763.Google Scholar
Hoagland, D. R. & Broyer, C. (1936). General nature of the process of salt accumulation by roots with description of experimental methods. Pl. Physiol., Lancaster 11, 471507.Google Scholar
I.B.M. (1967). Continuous System Modeling Program (360A-CX-16X), Users Manual. New York: I. B. M. publications.Google Scholar
Le, Mare P. H. (1968). Experiments on the effect of phosphate applied to a Uganda soil. II. Field experiments on the response curve. J. agric. Sci., Camb. 70, 271–9.Google Scholar
Loneragan, J. F. & Asher, C. J. (1967). Response of plants to phosphate concentration in solution culture. II. Rate of phosphate absorption and its relation to growth. Soil Sci. 103, 311–18.Google Scholar
Mitscherlich, E. A. (1909). Das Gesetz des Minimums und das Gesetz des abnehmenden Bodenortrages. Landw. Jb. 38, 537–52.Google Scholar
Nichols, M. A. (1971). Ph. D. Thesis, University of Massey, New Zealand.Google Scholar
Nye, P. H. & Tinker, P. B. (1969). The concept of a root demand coefficient. J. appl. Ecol. 6, 293300.CrossRefGoogle Scholar
Scaife, M. A. (1968). Maize fertiliser experiments in Western Tanzania. J. agric. Sci., Camb. 70, 209–22.Google Scholar
Smith, R. & Scaife, M. A. (1973). The phosphorus requirement of lettuce. I. Use of P intensity estimates to predict the response curve. J. agric. Sci., Camb. 80, 111–17.Google Scholar
Ulrich, A. (1952). Physiological basis for assessing the nutritional requirements of plants. A. Rev. Pl. Physiol. 3, 207–28.Google Scholar
Van Den, Honert T. H. & Hooymans, J. J. (1955). On the absorption of nitrate by maize in water culture. Acta bot. neerl. 4, 376–84.Google Scholar