Biogeochemistry

, Volume 60, Issue 2, pp 181–190 | Cite as

Carbon isotope fractionation of methyl bromideduring agricultural soil fumigations

  • Markus Bill
  • Laurence G. Miller
  • Allen H. Goldstein
Article

Abstract

The isotopic composition ofmethyl bromide (CH3Br) has been suggestedto be a potentially useful tracer forconstraining the global CH3Br budget. Inorder to determine the carbon isotopiccomposition of CH3Br emitted from the mostsignificant anthropogenic application(pre-plant fumigation) we directly measured theδ13C of CH3Br released duringcommercial fumigation. We also measured theisotopic fractionation associated withdegradation in agricultural soil under typicalfield fumigation conditions. The isotopiccomposition of CH3Br collected in soilseveral hours after injection of the fumigantwas −44.5‰ and this value increased to −20.7‰over the following three days. The mean kineticisotope effect (KIE) associated withdegradation of CH3Br in agricultural soil(12‰) was smaller than the reported value formethylotrophic bacterial strain IMB-1, isolatedfrom previously fumigated agricultural soil,but was similar to methylotrophic bacterialstrain CC495, isolated from a pristine forestlitter zone. Using this fractionationassociated with the degradation of CH3Brin agricultural soil and the meanδ13C of the industriallymanufactured CH3Br (−54.4‰), we calculatethat the agricultural soil fumigation sourcehas a carbon isotope signature that ranges from−52.8‰ to −42.0‰. Roughly 65% ofindustrially manufactured CH3Br is usedfor field fumigations. The remaining 35% isused for structural and post-harvestfumigations with a minor amount used duringindustrial chemical manufacturing. Assumingthat the structural and post-harvest fumigationsources of CH3Br are emitted withoutsubstantial fractionation, we calculate thatthe δ13C of anthropogenicallyemitted CH3Br ranges from −53.2‰ to −47.5‰.

atmosphere carbon isotopes fractionation methyl bromide soil fumigation 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Bill M, Rhew RC, Weiss RF& Goldstein AH (2002) Carbon isotope ratios of methyl bromide and methyl chloride emitted from a coastal salt marsh. Geophys. Res. Lett. 29: 4-1–4-4Google Scholar
  2. Coleman DD, Risatti JB& Schoell M (1981) Fractionation of carbon and hydrogen isotopes by methane-oxidizing bacteria. Geochim. Cosmochim. Acta 45: 1033–1037Google Scholar
  3. Kalin RM, Hamilton JTG, Harper DB, Miller LG, Lamb C, Kennedy JT, Downey A, McCauley S& Goldstein AH (2001) Continuous flow stable isotope methods for study of δ13C fractionation during halomethane production and degradation. Rapid Commun. Mass Spectrom. 15: 357–363Google Scholar
  4. Kurylo MJ, Rodriguez JM, Andrea MO, Atlas EL, Blake DR, Butler JH, Lal S, Lary DJ, Midgley PM, Montzka SA, Novelli PC, Reeves CE, Simmonds PG, Steele LP, Sturges WT, Weiss RF& Yokouchi Y (1999) Short-lived ozone-related compounds. In: Albritton GM, Watson RT& Aucamp PJ (Eds) Scientific Assessment of Ozone Depletion: 1998, (pp 2.1–2.37). Report no. 44, World Meteorological Organization, GenevaGoogle Scholar
  5. Majewski MS, McChesney MM, Woodrow JE, Pruger JH& Seiber JN (1995) Aerodynamic measurements of methyl bromide volatilization from tarped and nontarped fields. J. Environ. Quality 24: 742–752Google Scholar
  6. McCauley SE, Goldstein AH& DePaolo DJ (1999) An isotopic approach for understanding the CH3Br budget of the atmosphere. Pro. Natl. Acad. Sci. U.S.A. 96: 10006–10009Google Scholar
  7. Miller LG, Connell TL, Guidetti JR& Oremland RS (1997) Bacterial oxidation of methyl bromide in fumigated agricultural soils. Appl. and Environ. Microbiology 63: 4346–4354Google Scholar
  8. Miller LG, Kalin RM, McCauley SE, Hamilton JTG, Harper DB, Millet DB, Oremland RS & Goldstein AH (2001) Large Carbon Isotope Fractionation Associated with Oxidation of Methyl Halides by Methylotrophic Bacteria. Proc. Natl. Acad. Sci. U.S.A. 98: 5833–5837Google Scholar
  9. Rhew RC Miller BR& Weiss RF (2000) Natural methyl bromide and methyl chloride emissions from coastal salt marshes. Nature 403: 292–295Google Scholar
  10. Yagi K, Williams J, Wang N-Y& Cicerone RJ (1993) Agricultural soil fumigation as a source of atmospheric methyl bromide. Proc. Natl. Acad. Sci. U.S.A. 90: 8420–8423Google Scholar
  11. Yagi K, Williams J, Wang N-Y& Cicerone RJ (1995) Atmospheric methyl bromide (CH3Br) from agricultural soil fumigations. Nature 267: 1979–1981Google Scholar
  12. Yates SR, Gan J, Ernst FF, Mutziker A& Yates MV (1996a) Methyl bromide emissions from a covered field: I. Experimental conditions and degradation in soil. J. Environ. Qual. 25: 184–192Google Scholar
  13. Yates SR, Ernst FF, Gan J, Gao F& Yates MV (1996b) Methyl bromide emissions from a covered field: II. Volatilization. J. Environ. Qual. 25: 192–202Google Scholar

Copyright information

© Kluwer Academic Publishers 2002

Authors and Affiliations

  • Markus Bill
    • 1
  • Laurence G. Miller
    • 2
  • Allen H. Goldstein
    • 1
  1. 1.University of California, Environmental Science, Policy & ManagementBerkeleyU.S.A.
  2. 2.USGSMenlo ParkU.S.A

Personalised recommendations