Advancement of the Acetylene Inhibition Technique Using Time Series Analysis on Air-Dried Floodplain Soils to Quantify Denitrification Potential

Geosciences

Thomas Hein¹  Elmar Fuchs²  Holger Rupp³  Mathias Scholz⁴  Christian Hecht⁴  UteSusanne Kaden⁴  Christiane Schulz-Zunkel⁴ 

[1] BOKU—University of Natural Resources and Life Sciences, Gregor-Mendel-Straße 33, 1180 Vienna, Austria;BfG—German Federal Institute of Hydrology, Am Mainzer Tor 1, 56068 Koblenz, Germany;Helmholtz Centre for Environmental Research, Department of Soil System Sciences, Falkenberg 55, 39615 Altmärkische Wische, Germany;UFZ—Helmholtz Centre for Environmental Research, Department of Conservation Biology, Permoserstraße 15, 04318 Leipzig, Germany;

关键词: denitrification potential;    acetylene inhibition technique;    rewetting;    floodplain soils;    riparian zone;    ecosystem services;   

DOI  :  10.3390/geosciences10110431

来源: DOAJ

【 摘 要 】

Denitrification in floodplain soils is one key process that determines the buffering capacity of riparian zones in terms of diffuse nitrate pollution. One widely used approach to measure the denitrification potential is the acetylene inhibition technique that requires fresh soil samples. We conducted experiments with air-dried soils using a time series analysis to determine the optimal rewetting period. Thus, air-dried soil samples from six different floodplain areas in Germany were rewetted for 1 to 13days to 100% water-filled pore space. We analyzed nitrogen accumulated as N₂O in the top of anaerobic flasks with and without acetylene by gas chromatography after four hours of incubation. We observed an overall optimal rewetting of at least seven days for complete denitrification. We also saw the strong influence of pH and field capacity on the denitrification product ratio; in soils with pH < 7, we hardly assumed complete denitrification, whereas the treatments with pH > 7 achieved stable values after seven days of rewetting. This advanced method provides the opportunity to carry out campaigns with large soil sample sizes on the landscape scale, as samples can be stored dry until measurements are taken.

【 授权许可】

Unknown