Use of the “Acetylene blockage” technique for assaying denitrification in a salt marsh

✍ Scribed by C. D. Raalte; D. G. Patriquin

• Publisher: Springer-Verlag
• Year: 1979
• Tongue: English
• Weight: 520 KB
• Volume: 52
• Category: Article
• ISSN: 0025-3162
• DOI: 10.1007/bf00389072

✦ Synopsis

The "acetylene blockage" technique was evaluated for measurement of denitrification in salt-marsh sediments (near Halifax, Nova Scotia, Canada). N20 in the gas phase of closed Spartina alterniflora marsh-sediment systems was analyzed with use of a thermal conductivity gas chromatograph sensitive to approximately 0.1 nmoles ml-1 gas. No N20 was detected for unfertilized sediment samples taken through the growing season and incubated in sealed buckets with 10% C2H 2. For sediment samples amended with nitrate and for enrichments, initial rates of N20 evolution were higher in the presence of 10% C2H 2 than in the absence of C2H2, but after longterm incubation N20 was consumed in some samples containing C2H 2 as well as in samples without C2H 2. In addition, total gaseous nitrogen (N 2 and N20) production in the absence of C2H 2 was higher than in the presence of C2H 2. Acetylene appears to be an inconsistent inhibitor of N20 reduction in salt-marsh sediments. The usefulness of the acetylene-denitrification technique in this habitat is, therefore, questionable.