Determination of Denitrification Rates

Depletion of nitrate and the formation of dinitrogen are, however, not exclusively coupled to denitrification, since the microbially mediated reduction utilizing reduced species like or Fe + might occur. Based on field observations, a number of studies invoke the reduction of nitrate by Mn + to form N instead of organic matter respiration (Aller 1990 Schulz et al. 1994 Luther etal. 1997,1998). 

The direct determination of denitrification rates has been carried out by a number of different methods which all have certain advantages and restrictions. It is beyond the scope of this chapter to describe all of these methods in detail so that we will only give a short summary of the general principles. A more detailed overview of this subject can be found, for example, in Koike and Sorensen (1988) Seitzinger et al. (1993) and Kana etal. (1998). 

The most important methods of measuring denitrification are (1) the detection of totally produced gas by incubation, (2) isotope-labeling methods with and N, and (3) the acetylene (C Hj) inhibition technique. 

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