Hostname: page-component-cd9895bd7-gbm5v Total loading time: 0 Render date: 2024-12-26T06:31:37.436Z Has data issue: false hasContentIssue false

The characterization of the humic complexes of soil organic matter

Published online by Cambridge University Press:  27 March 2009

W. G. C. Forsyth
Affiliation:
Macaulay Institute for Soil Research, Aberdeen

Extract

1. During the course of the alkali fractionation and the preparation of the humic precipitates, the qualitative characters of the fractions were followed by employing a standard hydrolysis with dilute acid. Humic acid itself was shown to be unhydrolysed by this reagent, and, therefore, the extent of hydrolysis of a humic fraction can be used as a criterion of purity.

2. Studies on the fractionation of the humic precipitate with aqueous, anhydrous, and alcoholic bases, led to the following conclusions:

(a) The humic precipitate as normally prepared i s always a mixture of true humic acid with varying amounts of co-precipitated material of a non-humic nature.

(b) This non-humic material is not an integral part of the humic molecules, it is merely co-precipitated and adsorbed contaminants.

(c) The non-humic material is differentiated from the humic acids by the following properties: (i) it is hydrolysable with acid; (ii) it does not give the characteristic nitro-humic compound on nitration.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1947

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

Beckley, V. A. (1921). J. Agric. Sci. 11, 66.Google Scholar
Eller, W. & Koch, K. (1920). Ber. dtsch. chem. Ges. 53, 1469.Google Scholar
Erdtman, H. (1926). Svensk kern. Tidskr. 38, 202.Google Scholar
Erdtman, H. (1933). Proc. Boy. Soc. A, 143, 177.Google Scholar
Erdtman, H. (1943). An Introduction to Pollen Analysis, chap. 2.Google Scholar
Feustel, I. C. & Byers, H. G. (1936). Soil Sci. 42, 11.Google Scholar
Fuchs, W. (1927). BrennstChemie, 8, 73.Google Scholar
Fuchs, W. (1928). BrennstChemie, 9, 298.Google Scholar
Fuchs, W. (1930). BrennstChemie, 11, 372.Google Scholar
Fuchs, W. (1931). BrennstChemie, 12, 266.Google Scholar
Kurschner, K. (1933). Proc. 2nd Int. Cong. Soil Sci. (1930), 2, 184.Google Scholar
Kurschner, K. & Hoffer, A. (1931). Chemikerztg, 55, 161, 182.Google Scholar
Leopold, H. (1928). BrennstChemie, 9, 215.Google Scholar
Miklauz, R. (1908). Z. Moork. Torfverw. 6, 285.Google Scholar
Norris, F. W. & Preece, I. A. (1930). Biochem. J. 24, 59.Google Scholar
Perkin, W. H. (1903). Proc. Chem. Soc., Lond., 19, 1370.Google Scholar
Perkin, A. G. (1905). J. Chem. Soc. 87, 107.Google Scholar
Waksman, S. A. & Stevens, K. (1930). J. industr. Engng Chem. (Anal, ed.), 2, 167.Google Scholar
Zetsche, F. & Reinhart, H. (1939). BrennstChemie, 20, 84.Google Scholar