title: Laboratory study of the emission of NO and N2O from some Belgian soils.
abstract: The NO, NO2 and N2O emission was measured, upon application of nitrate, ammonium and both, to four Belgian soils with different characteristics. The addition of NH 4 (+) caused higher NO and N2O emissions than the addition of no nitrogen, or the addition of NO 3 (-) . In contrast to the two soils with a pH of approximately 8 the two soils with a pH around 6 showed a considerable delay in production of both NO and N2O upon the application of the ammonium, probably due to the lag-period of nitrification. The soils with a pH of 8 gave higher emissions on the application of NH 4 (+) than the soils with a pH of 6. The emission of NO2 was found to be considerably lower than the NO emission from the soils. The NO/NO2 ratio varied between 5-25 at considerable NO emissions (>50 nmol kg(-1)). In the controls of soil 1 and soil 2, which showed very low NO emissions ratios of <1 were observed. The N2O/NO ratios varied between 5-20 when NO emissions were considerable (>50 nmol kg(-1)). Soil 3 and 4 gave lower N2O/NO ratios than soil 1 and 2. In the controls of soil 1 and soil 2, at low NO emissions, N2O/NO ratios of >300 were observed. Soil 3 and 4 gave higher NO/NO2 and lower N2O/NO ratios than soil 1 and 2.
authors.affiliation: Faculty Agricultural and Applied Biological Sciences, University of Ghent, Coupure 653, B-9000, Ghent, Belgium.
authors.forename: C J
authors.initials: CJ
authors.lastname: De Groot
authors.forename: A
authors.initials: A
authors.lastname: Vermoesen
authors.forename: O
authors.initials: O
authors.lastname: Van Cleemput