Nitrous oxide emissions from European agriculture – an analysis of variability and drivers of emissions from field experiments

[摘要] Nitrous oxide emissions from a network of agricultural experiments in Europewere used to explore the relative importance of site and management controlsof emissions. At each site, a selection of management interventions werecompared within replicated experimental designs in plot-based experiments.Arable experiments were conducted at Beano in Italy, El Encin in Spain,Foulum in Denmark, Logården in Sweden, Maulde in Belgium, Paulinenaue inGermany, and Tulloch in the UK. Grassland experiments were conducted atCrichton, Nafferton and Peaknaze in the UK, Gödöllö in Hungary,Rzecin in Poland, Zarnekow in Germany and Theix in France. Nitrous oxideemissions were measured at each site over a period of at least two yearsusing static chambers. Emissions varied widely between sites and as a resultof manipulation treatments. Average site emissions (throughout the studyperiod) varied between 0.04 and 21.21 kg N₂O-N ha⁻¹ yr⁻¹, withthe largest fluxes and variability associated with the grassland sites.Total nitrogen addition was found to be the single most importantdeterminant of emissions, accounting for 15% of the variance (usinglinear regression) in the data from the arable sites (p < 0.0001),and 77% in the grassland sites. The annual emissions from arable siteswere significantly greater than those that would be predicted by IPCCdefault emission factors. Variability of N₂O emissions within sitesthat occurred as a result of manipulation treatments was greater than thatresulting from site-to-site and year-to-year variation, highlighting theimportance of management interventions in contributing to greenhouse gasmitigation.

[学科分类] 地球化学与岩石