Evaluation of denitrification losses by the acetylene inhibition technique in a permanent ryegrass field (Lolium perenne L.) fertilized with animal slurry or ammonium nitrate

1994 ◽  
Vol 18 (4) ◽  
pp. 327-333 ◽  
Author(s):  
L. Schwarz ◽  
M. Kapp ◽  
G. Benckiser ◽  
J. C. G. Ottow
Keyword(s):  
Ammonium Nitrate ◽  
Lolium Perenne ◽  
Acetylene Inhibition ◽  
Lolium Perenne L ◽  
Animal Slurry ◽  
Acetylene Inhibition Technique ◽  
Inhibition Technique

Effects of nitrate and water content on acetylene inhibition technique bias when analysing soil denitrification rates under an aerobic atmosphere

Geoderma ◽  
2019 ◽  
Vol 334 ◽  
pp. 33-36 ◽  
Author(s):  
Haijing Yuan ◽  
Zhijun Zhang ◽  
Shuping Qin ◽  
Shungui Zhou ◽  
Chunsheng Hu ◽  
...  
Keyword(s):  
Water Content ◽  
Acetylene Inhibition ◽  
Acetylene Inhibition Technique ◽  
Inhibition Technique

scholarly journals Application of the <sup>15</sup>N gas-flux method for measuring in situ N<sub>2</sub> and N<sub>2</sub>O fluxes due to denitrification in natural and semi-natural terrestrial ecosystems and comparison with the acetylene inhibition technique

2016 ◽  
Vol 13 (6) ◽  
pp. 1821-1835 ◽  
Author(s):  
Fotis Sgouridis ◽  
Andrew Stott ◽  
Sami Ullah
Keyword(s):  
Terrestrial Ecosystems ◽  
15N Tracer ◽  
Acetylene Inhibition ◽  
Flux Method ◽  
Gas Flux ◽  
Acetylene Inhibition Technique ◽  
Land Use Types ◽  
N2o Fluxes ◽  
Inhibition Technique

Abstract. Soil denitrification is considered the most un-constrained process in the global N cycle due to uncertain in situ N2 flux measurements, particularly in natural and semi-natural terrestrial ecosystems. 15N tracer approaches can provide in situ measurements of both N2 and N2O simultaneously, but their use has been limited to fertilized agro-ecosystems due to the need for large 15N additions in order to detect 15N2 production against the high atmospheric N2. For 15N–N2 analyses, we have used an “in-house” laboratory designed and manufactured N2 preparation instrument which can be interfaced to any commercial continuous flow isotope ratio mass spectrometer (CF-IRMS). The N2 prep unit has gas purification steps and a copper-based reduction furnace, and allows the analysis of small gas injection volumes (4 µL) for 15N–N2 analysis. For the analysis of N2O, an automated Tracegas Preconcentrator (Isoprime Ltd) coupled to an IRMS was used to measure the 15N–N2O (4 mL gas injection volume). Consequently, the coefficient of variation for the determination of isotope ratios for N2 in air and in standard N2O (0.5 ppm) was better than 0.5 %. The 15N gas-flux method was adapted for application in natural and semi-natural land use types (peatlands, forests, and grasslands) by lowering the 15N tracer application rate to 0.04–0.5 kg 15N ha−1. The minimum detectable flux rates were 4 µg N m−2 h−1 and 0.2 ng N m−2 h−1 for the N2 and N2O fluxes respectively. Total denitrification rates measured by the acetylene inhibition technique in the same land use types correlated (r =  0.58) with the denitrification rates measured under the 15N gas-flux method, but were underestimated by a factor of 4, and this was partially attributed to the incomplete inhibition of N2O reduction to N2, under a relatively high soil moisture content, and/or the catalytic NO decomposition in the presence of acetylene. Even though relatively robust for in situ denitrification measurements, methodological uncertainties still exist in the estimation of N2 and N2O fluxes with the 15N gas-flux method due to issues related to non-homogenous distribution of the added tracer and subsoil gas diffusion using open-bottom chambers, particularly during longer incubation duration. Despite these uncertainties, the 15N gas-flux method constitutes a more reliable field technique for large-scale quantification of N2 and N2O fluxes in natural terrestrial ecosystems, thus significantly improving our ability to constrain ecosystem N budgets.

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