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Determination of nitrogen in soil by the Kjeldahl method

Published online by Cambridge University Press:  27 March 2009

J. M. Bremner
J. M. Bremner
Affiliation:
Rothamsted Experimental Station, Harpenden, Herts
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Extract

1. The reliability of the Kjeldahl method for the determination of nitrogen in soils has been investigated using a range of soils containing from 0·03 to 2·7% nitrogen.

2. The same result was obtained when soil was analysed by a variety of Kjeldahl procedures which included methods known to recover various forms of nitrogen not determined by Kjeldahl procedures commonly employed for soil analysis. From this and other evidence presented it is concluded that very little, if any, of the nitrogen in the soils examined was in the form of highly refractory nitrogen compounds or of compounds containing N—N or N—O linkages.

3. Results by the method of determining nitrogen in soils recommended by the Association of Official Agricultural Chemists were 10–37% lower than those obtained by other methods tested. Satisfactory results were obtained by this method when the period of digestion recommended was increased.

4. Ammonium-N fixed by clay minerals is determined by the Kjeldahl method.

5. Selenium and mercury are considerably more effective than copper for catalysis of Kjeldahl digestion of soil. Conditions leading to loss of nitrogen using selenium are defined, and difficulties encountered using mercury are discussed.

6. The most important factor in Kjeldahl analysis is the temperature of digestion with sulphuric acid, which is controlled largely by the amount of potassium (or sodium) sulphate used for digestion.

7. The period of digestion required for Kjeldahl analysis of soil depends on the concentration of potassium sulphate in the digest. When the concentration is low (e.g. 0·3 g./ml. sulphuric acid) it is necessary to digest for several hours; when it is high (e.g. 1·0 g./ml. sulphuric acid) short periods of digestion are adequate. Catalysts greatly affect the rate of digestion when the salt concentration is low, but have little effect when the salt concentration is high.

8. Nitrogen is lost during Kjeldahl analysis when the temperature of digestion exceeds about 400° C.

9. Determinations of the amounts of sulphuric acid consumed by various mineral and organic soils during Kjeldahl digestion showed that there is little risk of loss of nitrogen under the conditions usually employed for Kjeldahl digestion of soil. Acid consumption values for various soil constituents are given, from which the amounts of sulphuric acid likely to be consumed during Kjeldahl digestion of different types of soil can be calculated.

10. Semi-micro Kjeldahl methods of determining soil nitrogen gave the same results as macro-Kjeldahl methods.

11. The use of the Hoskins apparatus for the determination of ammonium is described.

12. It is concluded that the Kjeldahl method is satisfactory for the determination of nitrogen in soils provided a few simple precautions are observed. The merits and defects of different Kjeldahl procedures are discussed.

Type
Research Article
Information
The Journal of Agricultural Science , Volume 55 , Issue 1 , August 1960 , pp. 11 - 33
Copyright
Copyright © Cambridge University Press 1960

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References

REFERENCES

Alford, W. C. (1952). Analyt. Chem. 24, 881.CrossRefGoogle Scholar
Alves, J. A. & Alves, E. L. N. (1952). Melhoramento, 4, 135.Google Scholar
Anantakrishnan, S. V. & Srinivasa Pai, K. V. (1952). Proc. Indian Acad. Sci. A, 36, 229.Google Scholar
Ashton, F. L. (1936). J. Agric. Sci. 26, 239.CrossRefGoogle Scholar
Ashton, F. L. (1937). J. Soc. Chem. Ind., Lond., 56, 101 T.Google Scholar
Association of Official Agricultural Chemists (1955). Official Methods of Analysis of the Association of Official Agricultural Chemists, 8th ed.Washington: A.O.A.C.Google Scholar
Bal, D. V. (1925). J. Agric. Sci. 15, 454.CrossRefGoogle Scholar
Beet, A. E. (1954). J. Appl. Chem. 4, 373.CrossRefGoogle Scholar
Beet, A. E. (1955). Nature, Lond., 175, 513.CrossRefGoogle Scholar
Belcher, R. & Godbert, A. L. (1941). J. Soc. Chem. Ind., Lond., 60, 196 T.CrossRefGoogle Scholar
Bradstreet, R. B. (1954). Analyt. Chem. 26, 235.CrossRefGoogle Scholar
Bradstreet, R. B. (1957). Analyt. Chem. 29, 944.CrossRefGoogle Scholar
Bremner, J. M. (1959). J. Agric. Sci. 52, 147.CrossRefGoogle Scholar
Bremner, J. M. & Shaw, K. (1955). J. Agric. Sci. 46, 320.CrossRefGoogle Scholar
Bremner, J. M. & Shaw, K. (1958). J. Agric. Sci. 51, 22.CrossRefGoogle Scholar
Campbell, W. R. & Hanna, M. I. (1937). J. Biol. Chem. 119, 1.CrossRefGoogle Scholar
Chibnall, A. C., Rees, M. W. & Williams, E. F. (1943). Biochem. J. 37, 354.CrossRefGoogle Scholar
Clark, E. P. (1941). J. Ass. Off. Agric. Chem., Wash., 24, 641.Google Scholar
Collins, S. H. (1906). J. Soc. Chem. Ind., Lond., 25, 518.Google Scholar
Dhariwal, A. P. S. & Stevenson, F. J. (1958). Soil Sci. 86, 343.CrossRefGoogle Scholar
Dyck, A. W. J. & McKibbin, R. R. (1935). Canad. J. Res. B, 13, 264.CrossRefGoogle Scholar
Elek, A. & Sobotka, H. (1926). J. Amer. Chem. Soc. 48, 501.CrossRefGoogle Scholar
Forsyth, W. G. C. (1947). J. Agric. Sci. 37, 132.CrossRefGoogle Scholar
Friedrich, A. (1933). Die Praxis der quantitativen organischen Mikroanalyse. Leipzig: F. Deuticke.Google Scholar
Friedrich, A., Kühaas, E. & Schnürch, R. (1933). Z. physiol. Chem. 216, 68.CrossRefGoogle Scholar
Gunning, J. W. (1889). Z. anal. Chem. 28, 188.CrossRefGoogle Scholar
Hiller, A., Plazin, J. & Van Slyke, D. D. (1948). J. Biol. Chem. 176, 1401.CrossRefGoogle Scholar
Hoskins, J. L. (1944). Analyst, 69, 271.Google Scholar
Jackson, M. L. (1958). Soil Chemical Analysis. Englewood Cliffs: Prentice-Hall.Google Scholar
Jonnard, R. (1945). Industr. Engng Chem. (Anal, ed.), 17, 246.Google Scholar
Kirk, P. L. (1947). Advanc. Protein Chem. 3, 139.CrossRefGoogle Scholar
Kirk, P. L. (1950). Analyt. Chem. 22, 354.CrossRefGoogle Scholar
Kjeldahl, J. (1883). Z. anal. Chem. 22, 366.CrossRefGoogle Scholar
Lake, G. R. (1952). Analyt. Chem. 24, 1806.CrossRefGoogle Scholar
Lake, G. R., McCutchan, P., Van Meter, R. & Neel, J. C. (1951). Analyt. Chem. 23, 1634.CrossRefGoogle Scholar
Lauro, M. F. (1931). Industr. Engng Chem. (Anal, ed.), 3, 401.Google Scholar
Markham, R. (1942). Biochem. J. 36, 790.CrossRefGoogle Scholar
McCutchan, P. & Roth, W. F. (1952). Analyt. Chem. 24, 369.CrossRefGoogle Scholar
McKenzie, H. A. & Wallace, H. S. (1954). Aust. J. Chem. 7, 55.CrossRefGoogle Scholar
McKibbin, R. R., Snell, J. F. & Dyck, A. W. J. (1935). Trans. 3rd Int. Congr. Soil Sci. 1, 419.Google Scholar
Middleton, G. & Stuckey, R. E. (1951). J. Pharm., Lond., 3, 829.CrossRefGoogle Scholar
Murneek, A. E. & Heinze, P. H. (1937). Res. Bull. Mo. Agric. Exp. Sta. no. 261.Google Scholar
Ogg, C. L. & Willits, C. O. (1950). J. Ass. Off. Agric. Chem., Wash., 33, 100.Google Scholar
Olsen, C. (1929). C.R. Lab. Carlsberg, 17, no. 15.Google Scholar
Patel, S. M. & Sreenivasan, A. (1948). Analyt. Chem. 29, 63.CrossRefGoogle Scholar
Perrin, C. H. (1953). Analyt. Chem. 25, 968.CrossRefGoogle Scholar
Piper, C. S. (1944). Soil and Plant Analysis. Adelaide: University of Adelaide.Google Scholar
Robinson, J. B. D. (1956). Analyst, 81, 316.CrossRefGoogle Scholar
Rodrigues, G. (1954). J. Soil Sci. 5, 264.CrossRefGoogle Scholar
Secor, G. E., Long, M. C., Kilpatrick, M. D. & White, L. M. (1950). J. Ass. Off. Agric. Chem., Wash., 33, 872.Google Scholar
Self, P. A. W. (1912). Pharm. J. 88, 384.Google Scholar
Shaw, K. (1959). J. Soil Sci. 10, 316.CrossRefGoogle Scholar
Shinn, M. B. (1941). Industr. Engng Chem. (Anal, ed.), 13, 33.Google Scholar
Srinivasan, A. (1932). Indian J. Agric. Sci. 2, 525.Google Scholar
Steyermark, A., McGee, B. E., Bass, E. A. & Kaup, R. R. (1958). Analyt. Chem. 30, 1561.CrossRefGoogle Scholar
Tinsley, J. (1950). Trans, 4th Int. Congr. Soil Sci. 1, 161.Google Scholar
Walkley, A. (1935). J. Agric. Sci. 25, 598.CrossRefGoogle Scholar
White, L. M., Secor, G. E. & Long, M. D. C. (1948). J. Ass. Off. Agric. Chem., Wash., 31, 657.Google Scholar
Willits, C. O., Coe, M. R. & Ogg, C. L. (1949). J. Ass. Off. Agric. Chem., Wash., 32, 118.Google Scholar