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| Eriksen, J.; Ledgard, S.; Lou, J.; Schils, R.; Rasmussen, J.. |
| Large nitrogen (N) surplus and return of excreta-N in localised patches at high N rates in intensively grazed pasture systems markedly increases the risk of N losses to waterways and the atmosphere. Here are described the main routes of N input to grazed pastures, losses via N leaching, methane (CH4) and nitrous oxide (N2O) emissions. Furthermore farm N budgets and N use efficiency in relation to management strategies that can be applied to reduce N losses are discussed. Nitrate leaching increases exponentially with increased inputs and is closely related to urine patches, which also influence the leaching of dissolved organic N. High N2O emission rates in grazed pastures are related to fertiliser-N or N in excreta combined with compaction by animal... |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Air and water emissions; Farm nutrient management. |
| Ano: 2010 |
URL: http://orgprints.org/17879/4/17879.pdf |
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| Ledgard, S.; Schils, R.; Eriksen, J.; Luo, J.. |
| Grazed clover/grass pastures are important for animal production systems and the clover component is critical for its contribution to nitrogen (N) inputs via biological fixation of atmospheric N2. The resource efficiency and environmental emissions for clover/grass pastures can differ from that of N-fertilised grass-only pastures. Clover N2 fixation uses photosynthetically-fixed carbon, whereas N fertiliser production consumes fossil fuels and has net greenhouse gas (GHG) emissions. Clover has a higher phosphorus (P) requirement than grass and where extra P fertiliser is used for clover/grass pastures the risk of P loss to waterways is greater than for grass-only pastures. Nitrogen leaching from grazed pasture increases exponentially with increased N... |
| Tipo: Journal paper |
Palavras-chave: Environmental aspects; Farm nutrient management. |
| Ano: 2009 |
URL: http://orgprints.org/17874/4/17874.pdf |
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| Schils, R.L.M.; Eriksen, J.; Ledgard, S.; Vellinga, T.V.; Kuikman, P.J.; Lou, J.; Petersen, S.O.; Velthof, G.L.. |
| Herbivores are a significant source of nitrous oxide (N2O) emissions. They account for a large share of manure-related N2O emissions, as well as soil-related N2O emissions through the use of grazing land, and land for feed and forage production. It is widely acknowledged that mitigation measures are necessary to avoid an increase in N2O emissions while meeting the growing global food demand. The production and emissions of N2O are closely linked to the efficiency of nitrogen (N) transfer between the major components of a livestock system, that is, animal, manure, soil and crop. Therefore, mitigation options in this paper have been structured along these N pathways. Mitigation technologies involving diet-based intervention include lowering the CP content... |
| Tipo: Journal paper |
Palavras-chave: Farming Systems; Air and water emissions. |
| Ano: 2012 |
URL: http://orgprints.org/20634/4/20634.pdf |
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