Potential Denitrification: Concept and Conditions of Its Measurement

Abstract

Denitrification plays important roles in nitrogen cycling and management affecting both the environment and agricultural systems. Potential denitrification has a role in comparison of denitrification magnitudes in different soils. This paper discusses the concept of potential denitrification in relation to denitrification rate and conditions under which it is determined. The terminologies such as denitrification activity, intensity, capacity and potential are variously applied to describe denitrification rates, but the use of these terms is not consistent. Similarly, the concept of potential denitrification is variously espoused. Many researchers measure potential denitrification under entirely different conditions, and express the values in divergent units making meaningful comparisons between soils unfeasible. It is proposed that the concept of potential denitrification embraces the principle of maximum attainable denitrification rate under optimal conditions within the limitations of natural setting. The steepest slope, ΔY/ΔX, on the cumulative nitrous oxide production–time curve defines the potential denitrification value. The conditions under which potential denitrification is to be measured, and the units in which its values are to be expressed are discussed.

Keywords:

• Biological denitrification
• Denitrification rates
• Potential denitrification

Acknowledgments

The author wishes to thank Prof. Oene Oenema and Dr. Bert Janssen, both of the Department of Environmental Science, Wageningen University, the Netherlands, for their valuable comments and suggestions.