Hostname: page-component-5c6d5d7d68-wtssw Total loading time: 0 Render date: 2024-08-19T23:03:51.988Z Has data issue: false hasContentIssue false
  • English
  • Français

Nitrate fluctuations in tropical soils

Published online by Cambridge University Press:  27 March 2009

D. J. Greenland
D. J. Greenland
Affiliation:
University College of Ghana
Get access Rights & Permissions [Opens in a new window]

Extract

The soil nitrate content has been determined at fortnightly intervals on bare fallow plots and on plots under crops and natural vegetation in the forest and savannah regions of Ghana. Nitrifiable nitrogen, ammonium and soil moisture contents have also been determined. It has been found that the changes in nitrate content are related to changes in the content of nitrifiable nitrogen. During the dry season, a partial sterilization of the soil occurs and consequently the content of nitrifiable nitrogen rises. This nitrifiable nitrogen is slowly converted to nitrate in the dry season and rapidly converted once the rains commence. Nitrate is then lost from the soil by leaching and denitrification. Under bare fallow conditions leaching is the most important cause of nitrate loss, but it is probable that denitrification makes some contribution on cropped soils and those under permanent vegetation. There is no indication of microbial nitrate absorption under a crop. This is presumably due to the rapidity with which nitrate is lost by leaching and denitrification, and to the greater quantity of organic matter required in these free-draining tropical soils than in most temperate ones to produce an equivalent absorption of nitrate. The high levels of nitrate and nitrifiable nitrogen which are found under natural forest probably represent an equilibrium level typical of a cycle in which nitrogen fixation and nitrification as well as nitrate losses proceed very rapidly. Natural savannah grassland suppresses nitrogen mineralization in the field almost entirely, but the nitrifiable nitrogen content is at times high, in spite of the very high carbon/nitrogen ratio of the soil of over 20. This confirms the view that little nitrate absorption takes place in spite of the presence of what might be considered excess carbonaceous material. The suppression of mineralization under grass is considered due to an excretion of the plant roots which is toxic to the nitrification process. The failure of organic matter to build up in these savannah soils, although mineralization is suppressed, is most probably associated with their low general fertility.

Type
Research Article
Information
The Journal of Agricultural Science , Volume 50 , Issue 1 , February 1958 , pp. 82 - 92
Copyright
Copyright © Cambridge University Press 1958

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Acharya, C. N., Parthasarthy, C. & Sabnis, C. V. (1946). Indian J. Agric. Sci. 16, 90.Google Scholar
Albrecht, W. A. (1934). J. Amer. Soc. Agron. 26, 569.CrossRefGoogle Scholar
Annett, H. E., Aiyer, A. R. P. & Kayasth, R. N. (1928). Mem. Dep. Agric. India, Chem. 9, 155.Google Scholar
Audus, L. J. (1946). Nature, Lond., 158, 419.CrossRefGoogle Scholar
Baumann, H. & Schendel, U. (1952). Z. Acker- u. PflBau, 95, 47.Google Scholar
Birch, H. F. & Friend, M. T. (1956). Nature, Lond., 178, 500.CrossRefGoogle Scholar
Bizzell, J. A. (1944). Mem. Cornell Agric. Exp. Sta., no. 256.Google Scholar
Chase, F. E. (1948). Sci. Agric. 28, 315.Google Scholar
Clark, F. E. (1949). Advanc. Agron. 1, 241.CrossRefGoogle Scholar
Dhar, N. R., Bhattacharya, A. K. & Biswas, N. N. (1933). Soil Sci. 35, 281.CrossRefGoogle Scholar
Diamond, W. E. de B. (1937). Emp. J. Exp. Agric. 5, 264.Google Scholar
Dommergues, Y. (1956). Trans. Sixth Int. Congr. Soil Sci., Paris, E, 605.Google Scholar
Drouineau, G. & Le Fèvre, G. (1949). Ann. agron., Paris, 19, 518.Google Scholar
Greene, H. (1935). Trans. Third. Int. Congr. Soil Sci., Oxford, 1, 217.Google Scholar
Greene, H. (1957). Private communication.Google Scholar
Greenland, D. J. (1956). Trans. Sixth. Int. Congr. Soil Sci., Paris, B, 765.Google Scholar
Griffith, G. ap (1951). Emp. J. Exp. Agric. 19, 1.Google Scholar
Griffith, G. ap & Manning, H. L. (1949). Trop. Agriculture, Trin., 26, 108.Google Scholar
Hall, T. D. (1921). Soil Sci. 12, 301.CrossRefGoogle Scholar
Hardy, F. (1946). Trop. Agriculture, Trin., 23, 40.Google Scholar
Harmsen, G. W. (1951). Plant and Soil, 3, 110.CrossRefGoogle Scholar
Harmsen, G. W. & Van Schreven, D. A. (1955). Advanc. Agron. 7, 299.CrossRefGoogle Scholar
Hartley, K. T. & Greenwood, M. (1933). Emp. Exp. Agric. 1, 113.Google Scholar
Hiltner, K. & Störmer, K. (1903). Arb. GesundhAmt, Berl., 3, 445.Google Scholar
Horne, W. R. & Denmead, O. T. (1955). J. Aust. Inst. Agric. Sci. 21, 34.Google Scholar
Jenny, H. (1950). Soil Sci. 69, 63.CrossRefGoogle Scholar
Jenny, H., Gessell, S. P. & Bingham, F. T. (1949). Soil Sci. 68, 419.CrossRefGoogle Scholar
Jewitt, T. N. (1945). J. Agric. Sci. 35, 264.CrossRefGoogle Scholar
Jewitt, T. N. (1950). J. Agric. Sci. 40, 160.CrossRefGoogle Scholar
Jewitt, T. N. (1956). J. Agric. Sci. 47, 461.CrossRefGoogle Scholar
Jones, T. (1956). Trans. Sixth Int. Congr. Soil Sci., Paris, B, 417.Google Scholar
Kowal, J. M. L. (1957). Private communication.Google Scholar
Leather, J. W. (1911). Mem. Dep. Agric. India, Chem. 2, 62.Google Scholar
Lebedjantzev, A. N. (1924). Soil Sci. 18, 419.CrossRefGoogle Scholar
Leutenegger, F. (1956). East African Agric. J. 22, 81.CrossRefGoogle Scholar
Martin, A. E. & Cox, J. E. (1956). Aust. J. Agric. Res. 7, 169.CrossRefGoogle Scholar
Nye, P. H. (1951). Emp. J. Exp. Agric. 19, 275.Google Scholar
Nye, P. H. (1952). Emp. J. Exp. Agric. 20, 47.Google Scholar
Prescott, J. A. (1920). J. Agric. Sci. 10, 177.CrossRefGoogle Scholar
Prescott, J. A. & Piper, G. R. (1930). J. Agric. Sci. 20, 517.CrossRefGoogle Scholar
Rao, G. G. & Dhar, N. R. (1931). Soil Sci. 31, 379.CrossRefGoogle Scholar
Richardson, H. L. (1938). J. Agric. Sci. 28, 73.CrossRefGoogle Scholar
Ruinen, J. (1956). Nature, Lond., 177, 220.CrossRefGoogle Scholar
Russell, E. J. & Hutchinson, H. B. (1909). J. Agric. Sci. 3, 111.CrossRefGoogle Scholar
Russell, E. J. & Hutchinson, H. B. (1912). J. Agric. Sci. 5, 152.CrossRefGoogle Scholar
Russell, E. W. (1950). Soil Conditions and Plant Growth. London: Longmans.Google Scholar
Soils and Fertilizers (1948). Soils & Fert. 11, 357.Google Scholar
Stiven, G. (1952). Nature, Lond., 170, 712.CrossRefGoogle Scholar
Taylor, C. J. (1952). Bull. Gold Coast Forestry Dept. no. 4.Google Scholar
Theron, J. J. (1949). Bull. S. Afr. Dep. Agric. Sci. no. 288.Google Scholar
Theron, J. J. (1951). J. Agric. Sci. 41, 289.CrossRefGoogle Scholar
Theron, J. J. & Haylett, D. G. (1953). Emp. J. Exp. Agric. 21, 86.Google Scholar
Vine, H. (1953). Emp. J. Exp. Agric. 21, 65.Google Scholar
Waksman, S. A. & Starkey, R. L. (1923). Soil Sci. 16, 137.CrossRefGoogle Scholar
Walker, T. W., Orchiston, H. D. & Adams, A. F. R. (1954). J. Brit. Grassl. Soc. 9, 249.CrossRefGoogle Scholar