Rees, R M2; Agustin, J3; Alberti, G4; Ball, B C2; Boeckx, P5; Canterel, A6; Castaldi, S7; Chirinda, Ngoni19; Chojnicki, B8; Giebels, M2; Gordon, H2; Grosz, B9; Horvath, R10; Juszczak, R8; Klemedtsson, Å K11; Klemedtsson, L11; Medinets, S12; Machon, A9; Mapanda, F13; Nyamangara, J14; Olesen, Jørgen E19; Reay, D S15; Sanchez, L16; Sanz Cobena, A16; Smith, K A15; Sowerby, A17; Sommer, M3; Soussana, J F6; Stenberg, M18; Topp, C F E2; van Cleemput, O5; Vallejo, A16; Watson, C A2; Wuta, M13
1 Department of Agroecology - Climate and Water, Department of Agroecology, Science and Technology, Aarhus University2 Scotland's Rural College (SRUC)3 ZALF4 University of Udine5 Ghent University6 INRA7 University of Naples8 Poznan University of Life Sciences9 Eötvös Loránd University10 Szent István University11 University of Gothenburg12 Odessa National II Mechnikov University13 University of Zimbabwe14 Matopos Research Station15 University of Edinburgh16 Polytechnic University of Madrid17 Centre for Ecology and Hydrology18 Swedish University of Agricultural Sciences19 Department of Agroecology - Climate and Water, Department of Agroecology, Science and Technology, Aarhus University
Nitrous oxide emissions from a network of agricultural experiments in Europe were used to explore the relative importance of site and management controls of emissions. At each site, a selection of management interventions were compared 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 in Germany, and Tulloch in the UK. Grassland experiments were conducted at Crichton, Nafferton and Peaknaze in the UK, Gödöllö in Hungary, Rzecin in Poland, Zarnekow in Germany and Theix in France. Nitrous oxide emissions were measured at each site over a period of at least two years using static chambers. Emissions varied widely between sites and as a result of manipulation treatments. Average site emissions (throughout the study period) varied between 0.04 and 21.21 kg N2O-N ha−1 yr−1, with the largest fluxes and variability associated with the grassland sites. Total nitrogen addition was found to be the single most important determinant of emissions, accounting for 15% of the variance (using linear regression) in the data from the arable sites (p < 0.0001), and 77% in the grassland sites. The annual emissions from arable sites were significantly greater than those that would be predicted by IPCC default emission factors. Variability of N2O emissions within sites that occurred as a result of manipulation treatments was greater than that resulting from site-to-site and year-to-year variation, highlighting the importance of management interventions in contributing to greenhouse gas mitigation.