ABSTRACT
Denitrification is the biological reduction of nitrate (NO3 ) and nitrite (NO2) ions into
gaseous nitrogen (N) in the form of nitric oxide (NO), nitrous oxide (N2O), and dinitrogen
(N2) gases. In agricultural soils, inorganic N is an essential nutrient taken up by crop roots,
whereas gaseous N is largely lost from the root zone via off-gassing.
