Denitrification in grass swards is increased under elevated atmospheric CO2

E. M. Baggs, M. Richter, G. Cadisch, U. A. Hartwig

Research output: Contribution to journalArticlepeer-review

Abstract

Emissions of N2O and N2 were measured from Lolium perenne L. swards under ambient (36 Pa) and elevated (60 Pa) atmospheric CO2 at the Swiss free air carbon dioxide enrichment experiment following application of 11.2 g N m-2 as 15NH415NO3 or 14NH415NO3 (1 at.% excess 15N). Total denitrification (N2O + N2) was increased under elevated pCO2 with emissions of 6.2 and 19.5 mg 15N m-2measured over 22 d from ambient and elevated pCO2 swards, respectively, supporting the hypothesis that increased belowground C allocation under elevated pCO2 provides the energy for denitrification. Nitrification was the predominant N2O producing process under ambient pCO2 whereas denitrification was predominant under elevated pCO2. The N2-to-N2O ratio was often higher under elevated pCO2 suggesting that previous estimates of gaseous N losses based only on N2O emissions have greatly underestimated the loss of N by denitrification.

Original languageEnglish
Pages (from-to)729-732
Number of pages4
JournalSoil Biology and Biochemistry
Volume35
Issue number5
DOIs
Publication statusPublished - 1 May 2003

Keywords

  • Denitrification
  • Dinitrogen
  • Elevated atmospheric CO
  • Free air carbon dioxide enrichment
  • Nitrous oxide
  • Stable isotopes

Fingerprint Dive into the research topics of 'Denitrification in grass swards is increased under elevated atmospheric CO<sub>2</sub>'. Together they form a unique fingerprint.

Cite this