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Mineral nitrogen in tropical forest soils

Published online by Cambridge University Press:  27 March 2009

R. K. Cunningham
Affiliation:
West African Cocoa Research Institute, Ghana

Extract

1. Δmin-Nad is the most satisfactory measurement for assessing mineralizable-N in the tropical forest soils used; values are treble those for Δmin-Nf and then increase even further on storage. Comparisons of Δmin-Nad are pointless unless methods of sampling, drying, storing and incubating are standardized.

2. Δmin-Nad is correlated with total N and organic C but not pH.

3. Undisturbed tropical forest soils can produce very large quantities of mineral N, particularly in their surface layers. This probably accounts for the lack of N responses in these soils. More intensive cultivation of these soils is only possible when organic matter is preserved by protecting cleared soils.

4. Added nitrogen was leached more rapidly in these soils than in comparable temperate soils but was not fast enough to prevent absorption by plants.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1962

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References

REFERENCES

Brammer, H. (1958). Soils of Ghana. Accra, Ghana Dept. of Agric.Google Scholar
Bremner, J. M. & Shaw, K. (1955). J. Agric. Sci. 46, 320.CrossRefGoogle Scholar
Cooke, G. W. & Cunningham, R. K. (1958). J. Sci. Fd Agric. 9, 324.Google Scholar
Cornfield, A. H. (1952). J. Sci. Fd Agric. 3, 343.CrossRefGoogle Scholar
Cunningham, R. K. & Cooke, G. W. (1958). J. Sci. Fd Agric. 9, 317.Google Scholar
Cunningham, R. K. & Smith, R. W. (1961). Trop. Agric. 38, 13.Google Scholar
Cunningham, B. K. & Arnold, P. W. (1962). J. Sci. Fd Agric. 13, 213.CrossRefGoogle Scholar
Gasser, J. K. R. (1959). J. Sci. Fd Agric. 10, 192.CrossRefGoogle Scholar
Gasser, J. K. R. (1961 a). J. Sci. Fd Agric. 12, 562.Google Scholar
Gasser, J. K. R. (1961 b). J. Sci. Fd Agric. 12, 778.CrossRefGoogle Scholar
Nye, P. H. & Greenland, D. J. (1960). Commonw. Bur. Soil Tech. Comm. 51.Google Scholar
Saunder, D. H., Ellis, B. S. & Hall, A. (1957). J. Soil Sci. 8, 301.CrossRefGoogle Scholar
Walkley, A. & Black, I. A. (1934). Soil Sci. 37, 29.Google Scholar