US EPA

2277441 

Journal Article 

Acidic northern soils as sources of atmospheric nitrous acid (HONO) 

Maljanen, M; Yli-Pirila, P; Hytonen, J; Joutsensaari, J; Martikainen, PJ 

2013 

1 

Soil Biology and Biochemistry
ISSN: 0038-0717
EISSN: 1879-3428 

PERGAMON-ELSEVIER SCIENCE LTD 

OXFORD 

67 

94-97 

10.1016/j.soilbio.2013.08.013 

WOS:000327107700012 

The photolysis of nitrous acid (HONO) is an important source of OH radical, the key oxidizing agent in the atmosphere. Recently it has been reported that nitrite (NO2-) in boil can also be a source of atmospheric HONO, in addition to the other pathways, e.g. the hydrolysis of nitrogen dioxide (NO2) on wet surfaces. However, the production rates of MONO in various soils are unknown. We selected a range of dominant northern acidic soils and showed in microcosm experiments that soils which have the highest nitrous oxide (N2O) and nitric oxide (NO) emissions (drained peatlands) also have the highest MONO production rates. It is known that in natural peatlands with high water table and in boreal coniferous forest soils, low nitrification activity (microbial production of nitrite and nitrate) limits their N2O production. Low availability of nitrite in these soils is the likely reason also for their low MONO production rates. Lowering of water table of peatlands as a result of drainage or climate change enhances their nitrification activity and N2O/NO production and as shown here also their HONO production. Also nitrogen deposition, or nitrogen fertilization and other land-use practices increasing availability of mineral nitrogen can be expected to enhance HONO emissions from soils. (C) 2013 Elsevier Ltd. All rights reserved. 

Nitrous acid; Nitrogen oxides; Ecosystems; Soil; Nitrite; Emission