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Use of Acetylene Reduction for Estimating Nitrogen Fixation in Woody Debris
Author(s) -
Hendrickson O. Q.
Publication year - 1988
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1988.03615995005200030043x
Subject(s) - nitrogen , acetylene , chemistry , nitrogen fixation , moisture , zoology , biology , organic chemistry
Both endogenous C 2 H 4 formation and C 2 H 4 arising from reduction of C 2 H 2 must be accurately measured in N 2 fixation studies using C 2 H 2 reduction. Previous work with forest soil has shown that C 2 H 4 formed in air is not an appropriate control for endogenous C 2 H 4 formation. This study compared different controls for endogenous C 2 H 4 formation during C 2 H 2 reduction studies of woody logging debris. Amounts of C 2 H 4 formed by decaying wood in the presence of C 2 H 2 plus either of two noncompetitive inhibitors of C 2 H 2 reduction (CO, (NH 4 ) 2 SO 4 ) were greater ( p <0.01) than amounts of C 2 H 4 formed in air. Ambient air controls therefore underestimated endogenous C 2 H 4 formation, and would overestimate N 2 fixation rates. Controls using (NH 4 ) 2 SO 4 were not suitable for routine use due to alteration of sample moisture content. With CO as an inhibitor, endogenous C 2 H 4 formation averaged 23% of total C 2 H 4 formed in the presence of C 2 H 2 across a range of moisture contents. Field data on C 2 H 4 produced by logging slash in the presence of C 2 H 2 alone are discussed in light of these findings. In the future, C 2 H 2 reduction studies of N 2 fixation in decaying wood should employ CO controls for endogenous C 2 H 4 formation.