EMISSIONS OF NO AND N2O FROM SOILS

Nitric oxide (NO) and nitrous oxide (N2O) fluxes were measured from ag ricultural, forest and moorland environments, using chamber techniques . Maximum emissions of NO and N2O were measured from the agricultural soils shortly after fertiliser application (7 ng N2O-N m-2 s-1 and 91 ng N2O-N m-2 s-1). For the non-agricultural soils the NO flux ranged f rom -0.3 to 0.5 ng N2O-N m-2 s-1 and the N2O flux ranged from 1 to 2.7 ng N2O-N m-2 s-1. Emissions, however, were increased 2 to 7 fold when N deposition (uplands) and N fixation (alder plantations) contributed to the pool of soil available N. The best predictors of the NO emissi on were soil NO3- and soil temperature, accounting for 60% of the vari ability observed. The prediction of N2O was less successful. Only 30% of the variability could be explained by the soil NO3- and the soil mo isture content, soil temperature did not have a significant effect on the N2O emission.