Nitrite in soils: accumulation and role in the formation of gaseous N compounds

TLDR: In this article, Nitrous acid spontaneously decomposes preferentially to NO and NO2 under acidic conditions (pH < 5.5), and as a result of these reactions gaseous compounds such as NO, NO2, N2O and CH3ONO can be formed.

Abstract: Nitrite is an intermediary compound formed during nitrification as well as denitrifiication. It occasionally accumulates in soils and drainage water. The nitrite can then undergo transformations to gaseous nitrogen compounds such as NO and NO2. Soil pH controls the abiotic nitrite decomposition to a large extent. Under acidic conditions(pH <5.5), nitrous acid spontaneously decomposes preferentially to NO and NO2. Nitrite also undergoes reactions with metallic cations (especially ferrous iron) and with organic matter. As a result of these reactions gaseous compounds such as NO, NO2, N2O and CH3ONO can be formed. Through reaction of nitrite with phenolic compounds nitroand nitrosocompounds can be formed, building up organic N. With normal agricultural practices on slightly acidic soils, the nitrite instability usually does not lead to economically important N losses from soils. However, the compounds formed through its degradation or interaction with other soil constituents are linked to environmental problems such as tropospheric ozone formation, acid rain, the greenhouse effect and the destruction of the stratospheric ozone.