Biology and Fertility of Soils

, Volume 14, Issue 3, pp 219–222 | Cite as

Availability of organic carbon for denitrification of nitrate in subsoils

  • G. W. McCarty
  • J. M. Bremner
Article

Summary

Previous work in our laboratory indicated that the slow rate of denitrification in Iowa subsoils is not due to a lack of denitrifying microorganisms, but to a lack of organic C that can be utilized by these microorganisms for reduction of NO 3 . This conclusion was supported by studies showing that drainage water from tile drains under agricultural research plots contained only trace amounts of organic C and had very little, if any, effect on denitrification in subsoils. Aqueous extracts of surface soils promoted denitrification when added to subsoils, and their ability to do so increased with increase in their organic C content. Amendment of surface soils with corn and soybean residues initially led to a marked increase in the amounts of organic C in aqueous extracts of these soils and in the ability of these extracts to promote denitrification in subsoils, but these effects were short-lived and could not be detected after incubation of residue-treated soils for a few days. We conclude from these observations that water-soluble organic C derived from plant residues is decomposed so rapidly in surface soils that very little of this C is leached into subsoils, and that this largely accounts for the slow rate of denitrification of nitrate in subsoils.

Key words

Denitrification Nitrate Subsoils Organic carbon Denitrifying microorganisms Plant residues 

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References

  1. Blackmer AM, Bremner JM (1977) Gas chromatographic analysis of soil atmospheres. Soil Sci Soc Am J 41:908–912Google Scholar
  2. Francis AJ, Slater JM, Dodge CJ (1989) Denitrification in deep subsurface sediments. Geomicrobiology 7:103–116Google Scholar
  3. Genrich DA, Bremner JM (1972) A reevaluation of the ultrasonic vibration method of dispersing soils. Soil Sci Soil Am Proc 36:944–947Google Scholar
  4. Gross PJ (1984) Evaluation of the acetylene blockage method of measuring denitrification in soils. MS thesis, Iowa State UniversityGoogle Scholar
  5. Lind AM, Eiland F (1989) Microbiological characterization and nitrate reduction in subsurface soils. Biol Fertil Soils 8:197–203Google Scholar
  6. Malhi SS, Nyborg M, Solberg ED (1990) Potential for nitrate-N loss in central Alberta soils. Fert Res 25:175–178Google Scholar
  7. Parkin TB, Meisinger JJ (1989) Denitrification below the crop rooting zone as influenced by surface tillage. J Environ Qual 18:12–16Google Scholar
  8. Thompson CA, Libra RD, Hallberg GR (1986) Water quality related to agchemicals in alluvial aquifers in Iowa. In: Agricultural impacts on ground water. National Water Well Association, Dublin, Ohio, pp 224–242Google Scholar
  9. Tiedje JL (1982) Denitrification. In: Page AL, Miller RH, Keeney DR (eds) Methods of soil analysis, Part 2. Agronomy 9, Am Soc Agron, Madison, Wisconsin, pp 1011–1026Google Scholar
  10. Trudell MR, Gillham RW, Cherry JA (1986) An in-situ study of the occurrence and rate of denitrification in a shallow unconfined sand aquifer. J Hydrol 83:251–268Google Scholar
  11. Yeomans JC, Bremner JM (1988) A rapid and precise method for routine determination of organic carbon in soil. Commun Soil Sci Plant Anal 19:1467–1476Google Scholar
  12. Yeomans JC, Bremner JM, McCarty GW (1992) Denitrification capacity and denitrification potential of subsurface soils. Commun Soil Sci Plant Anal 23:919–927Google Scholar

Copyright information

© Springer-Verlag 1992

Authors and Affiliations

  • G. W. McCarty
    • 1
  • J. M. Bremner
    • 1
  1. 1.Department of AgronomyIowa State UniversityAmesUSA

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