This document specifies a laboratory test for characterizing the denitrifying enzyme activities in soils^[5]. It globally characterizes the transformation of the nitrate form to the nitrous oxide and dinitrogen forms. This method was first proposed by Reference [5] with the acronym DEA for Denitrifying Enzyme Activities. It is a standardized technique used in numerous scientific studies.

DEA estimates the process of denitrification of fresh soil samples incubated under optimal conditions of substrates (nitrate and carbon sources) and environment (anaerobiosis, controlled temperature) for the denitrification process. The de novo enzyme synthesis is blocked by the use of chloramphenicol. DEA is believed to represent the size of the denitrifying enzyme pool present in the soil sample at the time of sample collection.

This test is performed in laboratory on a composite of sieved samples collected at the plot scale. It can be performed on all types of soils sampled all over the year.