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Experiments on the effects of phosphate applied to a Buganda soil: II. Field experiments on the response curve to triple superphosphate

Published online by Cambridge University Press:  27 March 2009

P. H. Le Mare
Affiliation:
Cotton Research Corporation, Cotton Research Station, Namulonge, Uganda*

Summary

A sigmoid curve for response to superphosphate has been demonstrated in field experiments in a Buganda red clay loam. There was evidence that the curve was abnormal; with small dressings of triple superphosphate yield of cotton and beans, and their phosphorus uptake, were decreased, but these characters were increased with larger dressings. Heavy dressings, from 4 to 16 cwt triple superphosphate, increased yield of these crops. Similar effects were observed with maize during growth and maturity was advanced, but final yield of grain was not affected by applied phosphate. The suggestion is made that in a long growing period the maize was able to absorb adequate phosphorus, even though the phosphate intensity in the soil was low, to achieve its potential yield.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1968

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References

REFERENCES

Cochran, W. G. & Cox, G. M. (1957). Experimental Designs. New York: John Wiley and Sons, Inc. Ch. 11.Google Scholar
Farbrother, H. G. (1957). On an electrical resistance technique for the study of soil moisture problems in the field. I. Performance, design and installation of nylon/stainless steel resistance units. Emp. Gott. Grow. Rev. 34, 7189.Google Scholar
Kabaara, A. M. (1964). Progr. Reps. Exp. Stns Emp. Cott. Grow. Corp. Tanganyika Lake Regions, Season 1962–63, p. 12.Google Scholar
Le Mare, P. H. (1960). Observations on the phosphate potential of some tropical soils. Trans. 7th int. Congr. Soil Sot. (Madison, Wise. U.S.A.) 3, 600–3.Google Scholar
Le Mare, P. H. (1962). Progr. Rep. Exp. Stns Emp. Cott. Grow. Corp. Uganda, Season 1961–62 p. 23.Google Scholar
Le Mare, P. H. (1968a). Experiments on the effect of phosphate applied to a Buganda soil. I. Pot experiments on the response curve. J. agric. Sci., Camb. 70, 265–70.CrossRefGoogle Scholar
Mulder, E. G. (1954). Molybdenum in relation to growth of higher plants and micro-organisms. Pl. Soil 5, 368415.CrossRefGoogle Scholar
Perry, D. A. (1962). Phytotoxic symptoms on cotton after spraying with DDT. Emp. Cott. Grow. Rev. 39, 203–5.Google Scholar
Terman, G. L. (1960). Yield response in experiments with phosphorous fertilizers in relation to: I. Meaningful differences among sources on acid soils of the south eastern States. Proc. Soil Sci. Soc. Am. 24, 356–60.CrossRefGoogle Scholar
Watanabe, F. S. & Olsen, S. R. (1962). Colorimetric determinations of phosphorus in water extracts of soil. Soil Sci. 93, 183–8.CrossRefGoogle Scholar
Young, O. R. & Plucknett, D. L. (1966). Quenching the high phosphorus fixation of Hawaiian latosols. Proc. Soil Sci. Soc. Am. 30, 653–5.CrossRefGoogle Scholar