Nitrous oxide emissions and soil mineral nitrogen status following application of hog slurry and inorganic fertilisers to acidic soils under forage grass

This paper examined the influence of hog slurry and inorganic fertilizers on nitrous oxide (N2O) emissions and soil inorganic nitrogen (N) composition. Factors controlling N2O production were also identified. The study was comprised of 3 field experiments conducted during the summer months of 2005 on 2 acidic soils seeded with forage grass at a site in Nova Scotia. Treatments included hog slurry; ammonium sulphate; potassium nitrate; and an unamended control site. Emissions were measured using vented polyvinyl chloride static chambers. Gas fluxes and NO2 measurements were analyzed using gas chromatography. Data were then subjected to analysis of variance (ANOVA). N2O flux and soil mineral N data from each sampling day were analyzed separately. Cumulative N2O losses were also calculated. Results demonstrated that the addition of hog slurry resulted in lower N2O emissions than the samples containing potassium nitrate fertilizer. The study also demonstrated that nitrate (NO3) production drives NO2 production in acidic soils. It was concluded that further research is needed to verify results obtained during the study. 29 refs., 3 tabs., 3 figs