Hostname: page-component-78c5997874-mlc7c Total loading time: 0 Render date: 2024-11-03T05:36:07.608Z Has data issue: false hasContentIssue false
  • English
  • Français

The influence of plants on the mineralization of nitrogen and the maintenance of organic matter in the soil

Published online by Cambridge University Press:  27 March 2009

J. J. Theron
J. J. Theron
Affiliation:
University of Pretoria
Get access Rights & Permissions [Opens in a new window]

Extract

The influence of growing plants on nitrification in the soil was studied by means of small lysimeters of which four were planted to a perennial grass, four to an annual millet crop and four were left fallow.

Nitrification was entirely repressed under the grass from the second season after its establishment onwards, and did not take place even when the grass was dormant in winter. This was due to a direct influence of the living root, since in the fallow soil which was treated similarly, nitrification took place freely throughout the winter. Under the annual crop a repression of nitrification could be detected only towards maturity of the crop and the soil solution was completely depleted of nitrates at this period. Nitrification was resumed, however, immediately after the crop was ripe and had died off and continued through the winter.

During the period that nitrification was depressed replaceable ammonia made its appearance in the soil in more than normal quantities. This fact is hold to indicate that the plant exerts its influence on the mineralization of nitrogen in the soil by paralysing the autotrophic dehydrogenase system of the nitrifying organisms without interfering with the process of ammonification and not, as has been claimed, by excreting such quantities of carbonaceous matter that nitrates are reassimilated by micro-organisms.

By virtue of the constancy of the carbon-nitrogen ratio in soils this influence of plants on the mineralization of nitrogen has a very important bearing on the conservation of soil humus and consequently on any system of alternate husbandry. Some of its implications were discussed with particular reference to local fertilizer practice and field experience.

Type
Research Article
Information
The Journal of Agricultural Science , Volume 41 , Issue 4 , October 1951 , pp. 289 - 296
Copyright
Copyright © Cambridge University Press 1951

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

Bizzell, J. A. (1944). Mem. Cornell Univ. Agric. Exp. Sta. no. 256.Google Scholar
Broadbent, F. E. & Norman, A. G. (1946). Proc. Soil Sci. Soc. Amer. 11, 264.CrossRefGoogle Scholar
Burd, J. S. & Martin, J. C. (1923). Univ. Calif. Publ. (Tech. Paper), no. 13.Google Scholar
Burd, J. S. & Martin, J. C. (1931). Hilgardia, 5, no. 15, 455.CrossRefGoogle Scholar
Dehérain, P. P. (1902). Traité de chimie agricole, 568.Google Scholar
Dodds, H. H. (1944). S. Afr. Sug. J. 28, 467.Google Scholar
Dodds, H. H. (1945). S. Afr. Sug. J. 29, 525.Google Scholar
Gainey, P. L., Sewell, M. C. & Latshaw, W. L. (1929). J. Amer. Soc. Agron. 14, 320.Google Scholar
Goring, C. A. I. & Clark, F. E. (1948). Proc. Soil Sci. Soc. Amer. 13, 261.CrossRefGoogle Scholar
Jenny, H. (1950). Soil Sci. 69, 63.CrossRefGoogle Scholar
Leather, J. W. (1912). Mem. India Agric. Dep. (Chem. Series), 2, 62.Google Scholar
Lyon, T. L. & Bizzell, J. A. (1913). Mem. Cornell Univ. Agric. Exp. Sta. no. 12.Google Scholar
Lyon, T. L. & Wilson, J. K. (1921). Mem. Cornell Univ. Agric. Exp. Sta. no. 40.Google Scholar
Lyon, T. L., Bizzell, J. A. & Wilson, J. K. (1923). J. Amer. Soc. Agron. 15, 457.CrossRefGoogle Scholar
Lyon, T. L., Bizzell, J. A., Wilson, B. D. & Leland, E. W. (1930). Mem. Cornell Univ. Agric. Exp. Sta. no. 134.Google Scholar
Lyon, T. L. & Bizzell, J. A. (1936). Mem. Cornell Univ. Agric. Exp. Sta. no. 194.Google Scholar
Prescott, J. A. (1920). J. Agric. Sci. 10, 177.CrossRefGoogle Scholar
Richardson, H. L. (1935). Trans. 3rd Int. Congr. Soil Sci. V, 1, 219.Google Scholar
Richardson, H. L. (1938). J. Agric. Sci. 28, 73.CrossRefGoogle Scholar
Russell, E. J. (1914). J. Agric. Sci. 6, 50.CrossRefGoogle Scholar
Russell, E. J. (1937). Soil Conditions and Plant Growth, 7th ed.London: Longmans, Green and Co.Google Scholar
Sherrard, C. D. (1948). Proc. S. Afr. Sugar Tech. Assoc. pp. 119–25.Google Scholar
Theron, J. J. (1948). Sci. Bull. Dep. Agric. S. Afr., no. 288.Google Scholar
Waksman, S. A. (1927). Principles of Soil Microbiology. Baltimore: The Williams and Wilkens Co.CrossRefGoogle Scholar
Waksman, S. A. (1936). Humus. London: Baillière, Tindall and Cox.Google Scholar
Warrington, R. (1905). Trans. Highl. Agric. Soc. Scot. Ser. 5, 17, 148.Google Scholar
Wilcox, O. W. (1945). Sugar, 40, 36.Google Scholar