caa a22 4500 44538395X CHVBK 20180317143026.0 cr unu---uuuuu 170323e20110601xx s 000 0 eng 10.1007/s10021-011-9434-x doi (NATIONALLICENCE)springer-10.1007/s10021-011-9434-x Nitrous Oxide Emission from Grazed Grassland Under Different Management Systems [Elektronische Daten] [Rashad Rafique, Deirdre Hennessy, Gerard Kiely] Nitrous oxide (N2O) emissions from grazed grasslands are estimated to be approximately 28% of global anthropogenic N2O emissions. Estimating the N2O flux from grassland soils is difficult because of its episodic nature. This study aimed to quantify the N2O emissions, the annual N2O flux and the emission factor (EF), and also to investigate the influence of environmental and soil variables controlling N2O emissions from grazed grassland. Nitrous oxide emissions were measured using static chambers at eight different grasslands in the South of Ireland from September 2007 to August 2009. The instantaneous N2O flux values ranged from -186 to 885.6μg N2O-Nm−2h−1 and the annual sum ranged from 2±3.51 to 12.55±2.83kg N2O-Nha−1y−1 for managed sites. The emission factor ranged from 1.3 to 3.4%. The overall EF of 1.81% is about 69% higher than the Intergovernmental Panel on Climate Change (IPCC) default EF value of 1.25% which is currently used by the Irish Environmental Protection Agency (EPA) to estimate N2O emission in Ireland. At an N applied of approximately 300kgha−1y−1, the N2O emissions are approximately 5.0kg N2O-Nha−1 y−1, whereas the N2O emissions double to approximately 10kgNha−1 for an N applied of 400kgNha−1y−1. The sites with higher fluxes were associated with intensive N-input and frequent cattle grazing. The N2O flux at 17°C was five times greater than that at 5°C. Similarly, the N2O emissions increased with increasing water filled pore space (WFPS) with maximum N2O emissions occurring at 60-80% WFPS. We conclude that N application below 300kgha−1y−1 and restricted grazing on seasonally wet soils will reduce N2O emissions. Springer Science+Business Media, LLC, 2011 nitrous oxide nationallicence grassland nationallicence emission factor nationallicence nitrogen input nationallicence soil temperature nationallicence water filled pore space nationallicence grazing frequency nationallicence soil type nationallicence Rafique Rashad Department of Civil and Environmental Engineering, Centre for Hydrology, Micrometeorology and Climate Change, University College Cork, Cork, Ireland aut Hennessy Deirdre Department of Animals &, Grassland Science Research, Teagasc-Moorpark, Fermoy, Ireland aut Kiely Gerard Department of Civil and Environmental Engineering, Centre for Hydrology, Micrometeorology and Climate Change, University College Cork, Cork, Ireland aut Ecosystems Springer-Verlag 14/4(2011-06-01), 563-582 1432-9840 14:4<563 2011 14 10021 https://doi.org/10.1007/s10021-011-9434-x text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10021-011-9434-x text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Rafique Rashad Department of Civil and Environmental Engineering, Centre for Hydrology, Micrometeorology and Climate Change, University College Cork, Cork, Ireland aut NATIONALLICENCE 700 1- Hennessy Deirdre Department of Animals &, Grassland Science Research, Teagasc-Moorpark, Fermoy, Ireland aut NATIONALLICENCE 700 1- Kiely Gerard Department of Civil and Environmental Engineering, Centre for Hydrology, Micrometeorology and Climate Change, University College Cork, Cork, Ireland aut NATIONALLICENCE 773 0- Ecosystems Springer-Verlag 14/4(2011-06-01), 563-582 1432-9840 14:4<563 2011 14 10021 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer