Effects of organic matter on sulphur oxidation in soil and influence of sulphur oxidation on soil nitrification
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The effects of wheat straw and pressed sugar beet pulp on sulphur oxidation were determined in a loam soil amended with 1% (w/w) elemental sulphur. Wheat straw stimulated the oxidation of elemental sulphur over the first 2 to 3 weeks of the incubation period, resulting in an increase in LiCl-extractable sulphate. After 4 to 7 weeks incubation however, the only significant increase in soil sulphate followed the 1% straw addition, while at week 7 sulphate concentrations in the 0.25% and 5.0% straw amended soils were lower than the control.
Pressed sugar beet pulp (1% w/w) initially stimulated the oxidation of elemental sulphur in the soil, but by weeks 3 to 7 of the incubation period rates of oxidation in pulp-amended soils were lower than the control. Towards the end of the incubation period however, sulphate concentrations in the amended soils exceeded the control values, significantly so by week 11. The concentration of thiosulphate and tetrathionate also increased in soils receiving sugar beet pulp.
Nitrification was inhibited in soils in which sulphur oxidation was actively occurring. Although possible alternatives are mentioned, such inhibition appears to result from a decrease in soil pH brought about by the oxidation of elemental sulphur to sulphuric acid.
Key wordsNitrification Organic matter Sulphur cycle Sulphur oxidation
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- 1.Alexander M 1977 Introduction to Soil Microbiology. J. Wiley, New York.Google Scholar
- 2.Bettany J R, Janzen H H and Stewart J W B 1982 Sulphur deficiency in the Prairie Provinces of Canada.In Proc Intern Sulphur Conf. London. Ed. A E More. pp 787–800. British Sulphur Corporation, London.Google Scholar
- 3.Christian D G and Miller D P 1983 Straw residue management for autumn grown cereals: Influence of chop length and depth of straw incorporation. ARC Letcombe Lab. Ann. Rep. 32-34.Google Scholar
- 4.Focht D D and Verstraete W 1977 Biochemical ecology of nitrification and denitrification. Adv. Microbiol. Ecol. 1, 135–214.Google Scholar
- 6.Grayston S J, Nevell W and Wainwright M 1986 Sulphur oxidation by fungi. Trans. Br. Mycol. Soc. (In Press).Google Scholar
- 7.Hesse P R 1971 A Textbook of Soil Chemical Analysis. J Murray, London.Google Scholar
- 8.Lynch J M 1979 Straw residues as substrates for growth and product formation by soil microbes.In Straw Decay and its Effects on Disposal and Utilization. Ed. E Grossbard. pp 47–56. John Wiley, Chichester.Google Scholar
- 9.Maftoun M and Banihashemi Z 1981 Effects of added sulphur, aluminium sulfate and ferrous sulphate on CO2 evolution, microbial population and nitrification in alfalfa and straw amended soil. Agrochimica 25, 318–326.Google Scholar
- 10.Nor Y M and Tabatabai M A 1976 Extraction and colorimetric determination of thiosulphate and tetrathionate in soils. Soil Sci. 122, 171–175.Google Scholar
- 11.Nor Y M and Tabatabai M A 1977 Oxidation of elemental sulfur in soils. J. Soil Sci. Soc. Am. 41, 736–741.Google Scholar
- 12.Raistrick H and Vincent J M 1984 Studies in the biochemistry of microorganisms: A survey of fungal metabolism of inorganic sulphates. Biochem. J. 43, 90–99.Google Scholar
- 13.Saleh S M 1978 Competitive growth of Nitrosomonas and Nitrobacter in inorganic sulfur containing sandy soils. Libyan J. Agric. 7, 171–177.Google Scholar
- 14.Sims J R and Jackson G D 1971 Rapid analysis of soil nitrate with chromotropic acid. Soil Sci. Soc. Am. J. 35, 603–606.Google Scholar
- 15.Solberg E D, Nyborg M, Laverty D H and Malhi S S 1982 Oxidation of elemental sulphur used as a fertilizer. Proc. 19th Ann. Alberta Soil Sci. Workshop Edmonton 241–252.Google Scholar
- 16.Stotzky G and Norman A H G 1961 Factors limiting microbial activities in soil. Arch. Microbiol. 40, 370–372.Google Scholar
- 18.Wainwright M 1984 Sulfur oxidation in soils. Adv. Agron. 37, 349–396.Google Scholar
- 20.Widdowson J P and Blakemore L C 1982 The sulphur status of soils of the South West Pacific area.In Proc Intern Sulphur Conf London Vol 2. Ed. A E More. pp 805–819. British Sulphur Corporation, London.Google Scholar