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Registros recuperados: 44 | |
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Carter, Mette S.; Ambus, Per. |
The contribution of biologically fixed dinitrogen (N2) to the nitrous oxide (N2O) production in grasslands is unknown. To assess the contribution of recently fixed N2 as a source of N2O and the transfer of fixed N from clover to companion grass, mixtures of white clover and perennial ryegrass were incubated for 14 days in a growth cabinet with a 15N2-enriched atmosphere (0.4 atom% excess). Immediately after labelling, half of the grass-clover pots were sampled for N2 fixation determination, whereas the remaining half were examined for emission of 15N labelled N2O for another eight days using a static chamber method. Biological N2 fixation measured in grass-clover shoots and roots as well as in soil constituted 342, 38 and 67 mg N m-2 d-1 at 16, 26 and 36... |
Tipo: Journal paper |
Palavras-chave: Pasture and forage crops; Air and water emissions. |
Ano: 2006 |
URL: http://orgprints.org/10144/1/10144.pdf |
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Andersen, Mette Klindt; Hauggaard-Nielsen, Henrik; Ambus, Per; Jensen, Erik Steen. |
The interspecific complementary and competitive interactions between pea (Pisum sativum L.), barley (Hordeum vulgare L.) and oilseed rape (Brassica napus L.), grown as dual and tri-component intercrops were assessed in a field study in Denmark. Total biomass production and N use at two levels of N fertilisation (0.5 and 4.0 g N/m2), were measured at five harvests throughout a growing season. All intercrops displayed land equivalent ratio values close to or exceeding unity, indicating complementary use of growth resources. Whereas both rape and barley responded positively to increased N fertilisation, irrespective of whether they were grown as sole- or intercrops, pea was strongly suppressed when grown in intercrop. Of the three crops barley was the... |
Tipo: Journal paper |
Palavras-chave: Nutrient turnover; Crop combinations and interactions. |
Ano: 2004 |
URL: http://orgprints.org/6002/1/MKA.pdf |
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Carter, Mette S.; Hauggaard-Nielsen, Henrik; Johansen, Anders; Ambus, Per. |
Currently CO2 from fossil fuel combustion accounts for 57% of the global greenhouse gas emissions, whereas the strong greenhouse gases nitrous oxide (N2O) and methane (CH4) contribute with 8% and 14%, respectively (IPCC, 2007). Agricultural activity is the dominant source of N2O, which is mainly associated with the use of nitrogen based fertilizers in agricultural production. Replacing fossil fuel-derived energy by biomass-derived energy is commonly and with increasing emphasis proposed as a mean to mitigate the CO2 emissions. However, a recent analysis of global emission data proposes that accelerated emissions of N2O associated with the production of biomass for bio-fuel purposes will outweigh the avoided emissions of fossil fuel-derived CO2 (Crutzen et... |
Tipo: Conference paper, poster, etc. |
Palavras-chave: Nutrient turnover Recycling; Balancing and resource management Air and water emissions Composting and manuring. |
Ano: 2009 |
URL: http://orgprints.org/16179/1/16179.pdf |
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Carter, Mette S.; Hauggaard-Nielsen, Henrik; Heiske, Stefan; Jensen, Morten; Thomsen, Sune T.; Schmidt, Jens Ejbye; Johansen, Anders; Ambus, Per. |
One way of reducing the emissions of fossil fuel-derived carbon dioxide (CO2) is to replace fossil fuels with biofuels produced from agricultural biomasses or residuals. However, cultivation of soils results in emission of other greenhouse gasses (GHGs), especially nitrous oxide (N2O). Previous studies showed that field emissions of N2O may contribute significantly to total GHG emissions during biofuel production. Furthermore, N2O may counterbalance a considerable part of the global warming reduction, which is achieved by fossil fuel displacement. In the present study, we related measured field emissions of N2O to the reduction in fossil fuel-derived CO2, which was obtained when agricultural biomasses were used for biofuel production. The analysis included... |
Tipo: Journal paper |
Palavras-chave: Pasture and forage crops Cereals; Pulses and oilseeds Nutrient turnover Air and water emissions. |
Ano: 2012 |
URL: http://orgprints.org/20905/10/20905.pdf |
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Johansen, Anders; Carter, Mette S.; Jensen, Erik Steen; Hauggaard-Nielsen, Henrik; Ambus, Per. |
Anaerobic digestion of animal manure and crop residues may be employed to produce biogas as a climate-neutral source of energy to provide fertilizers which allow recycling of plant nutrients on the farm. However, compared to fertilizing with the pristine input materials (e.g. raw animal slurry or plant residues), the effect on soil microbiota and soil fertility may be impacted due to the increased content of mineral nitrogen (N) and decreased amount of organic carbon (C); an issue of concern in especially organic farming systems. An incubation study was performed where 1) water, 2) raw cattle slurry, 3) anaerobically digested cattle slurry + maize, 4) anaerobically digested cattle slurry + grass-clover, or 5) fresh grass-clover was applied to soil at... |
Tipo: Journal paper |
Palavras-chave: Soil quality; Nutrient turnover; Air and water emissions; Biodiversity and ecosystem services; Farm nutrient management. |
Ano: 2011 |
URL: http://orgprints.org/20446/4/20446.pdf |
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Johansen, Anders; Carter, Mette S.; Jensen, Erik Steen; Hauggaard-Nielsen, Henrik; Ambus, Per. |
Soil from the Højbakkegård experimental (BioConcens) field was amended with nothing (control), each of two anaerobic digested (AD) materials (mixture of AD cattle manure and maize, mixture of AD cattle manure and cut off grass-clover material), raw cattle manure, and grass-clover in five individual treat-ments. The materials were incorporated homogeneously into the soil and sampled destructively at 0, 1, 3 and 9 days after incorporation. Besides, experiments were performed to follow the turnover of these materials, measured as accumulated respiration over a longer period. Measures included available organic soil carbon (cold- and hot-water extractable), soil mineral nitrogen concentration, soil pH, accumulated respiration over a two-week period, emission... |
Tipo: Journal paper |
Palavras-chave: Soil quality; Nutrient turnover; Air and water emissions; Biodiversity and ecosystem services; Farm nutrient management. |
Ano: 2011 |
URL: http://orgprints.org/18894/7/18894.pdf |
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Carter, Mette S.; Sørensen, Peter; Petersen, Søren O.; Ambus, Per. |
Organic arable farming faces challenges with low crop yields, partly due to inefficient use of green manure-derived nitrogen (N). Under current farming practices, green manure leys are often cut and mulched during the growing season with the associated risk of environmental N losses, leading to eutrophication and global warming. In this 3-month incubation experiment, we tested a new green manure management strategy as part of the ICROFS project HighCrop. With the new strategy, green manure leys are instead harvested and preserved until the following spring either as compost mixed with straw (grass-clover:straw, 4:1, w:w) or as silage of harvested ley biomass. In spring, these two green manure materials can then be used for targeted fertilization of spring... |
Tipo: Conference paper, poster, etc. |
Palavras-chave: Nutrient turnover; Air and water emissions. |
Ano: 2013 |
URL: http://orgprints.org/25941/19/25941a.pdf |
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Carter, Mette S.; Sørensen, Peter; Petersen, Søren O.; Ma, Xiuzhi; Ambus, Per. |
More efficient use of green manure-derived nitrogen (N) may improve crop yields and reduce environmental impacts in stockless organic arable farming. In this 3-month incubation study, we tested a new strategy where green manure leys are harvested and preserved until the following spring either as compost mixed with straw (grass-clover:straw, 4:1, w:w) or as silage of harvested ley biomass. Grass-clover compost or silage was soil-incorporated by either simulated ploughing (green manure placed at 15 cm depth) or harrowing (green manure mixed into the upper 5-cm soil horizon) in order to assess treatment effects on net release of plant-available N, nitrous oxide (N2O) fluxes, and soil respiration. Grass-clover silage provided the highest net N release with... |
Tipo: Journal paper |
Palavras-chave: Nutrient turnover; Air and water emissions. |
Ano: 2013 |
URL: http://orgprints.org/24960/7/24960.pdf |
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Carter, Mette S.; Sørensen, Peter; Petersen, Søren O.; Ma, Xiuzhi; Ambus, Per. |
More efficient use of green manure-derived nitrogen (N) may improve crop yields and reduce environmental impacts in stockless organic arable farming. In this 3-month incubation study, we tested a new strategy where green manure leys are harvested and preserved until the following spring either as compost mixed with straw or as silage of harvested ley biomass. Grass-clover compost or silage was soil-incorporated by either simulated ploughing (green manure placed at 15 cm depth) or harrowing (green manure mixed into the upper 5-cm soil horizon) in order to assess treatment effects on net release of plant-available N, nitrous oxide (N2O) fluxes, and soil respiration. Grass-clover silage provided the highest net N release with similar results for the two... |
Tipo: Journal paper |
Palavras-chave: Nutrient turnover; Air and water emissions. |
Ano: 2014 |
URL: http://orgprints.org/25158/7/25158.pdf |
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Carter, Mette S.; Sørensen, Peter; Petersen, Søren O.; Ma, Xiuzhi; Ambus, Per. |
More efficient use of green manure-derived nitrogen (N) may improve crop yields and reduce environmental impacts in stockless organic arable farming. In this 3-month incubation study, we tested a new strategy where green manure leys are harvested and preserved until the following spring either as compost mixed with straw or as silage of harvested ley biomass. Grass-clover compost or silage was soil-incorporated by either simulated ploughing (green manure placed at 15 cm depth) or harrowing (green manure mixed into the upper 5-cm soil horizon) in order to assess treatment effects on net release of plant-available N, nitrous oxide (N2O) fluxes, and soil respiration. Grass-clover silage provided the highest net N release with similar results for the two... |
Tipo: Journal paper |
Palavras-chave: Nutrient turnover; Air and water emissions. |
Ano: 2014 |
URL: http://orgprints.org/27643/25/Carter%20et%20al.%202014_BFOS.pdf |
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Carter, Mette S.; Sørensen, Peter; Petersen, Søren O.; Ma, Xiuzhi; Ambus, Per. |
More efficient use of green manure-derived nitrogen (N) may improve crop yields and reduce environmental impacts in stockless organic arable farming. In this 3-month incubation study, we tested a new strategy where green manure leys are harvested and preserved until the following spring either as compost mixed with straw or as silage of harvested ley biomass. Grass-clover compost or silage was soil-incorporated by either simulated ploughing (green manure placed at 15 cm depth) or harrowing (green manure mixed into the upper 5-cm soil horizon) in order to assess treatment effects on net release of plant-available N, nitrous oxide (N2O) fluxes, and soil respiration. Grass-clover silage provided the highest net N release with similar results for the two... |
Tipo: Journal paper |
Palavras-chave: Nutrient turnover; Air and water emissions. |
Ano: 2014 |
URL: http://orgprints.org/26717/13/Carter%20et%20al.%202014_BFOS_online.pdf |
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Carter, Mette S.; Hauggaard-Nielsen, Henrik; Heiske, Stefan; Thomsen, Sune T.; Jensen, Morten; Schmidt, Jens Ejbye; Johansen, Anders; Ambus, Per. |
Field emissions of N2O during cultivation of bioenergy crops may counterbalance a considerable part of the avoided fossil CO2 emissions that are achieved by fossil fuel displacement |
Tipo: Conference paper, poster, etc. |
Palavras-chave: Nutrient turnover; Air and water emissions. |
Ano: 2011 |
URL: http://orgprints.org/18332/4/18332.pdf |
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Thyme, Mette; Ambus, Per. |
In organic dairy farming, a major N input to the plant-soil system comes from biological N2 fixation by pasture legumes, but knowledge is sparse on how much of the fixed N2 is lost from the pastures as N2O. Nitrifying and denitrifying bacteria are the main contributors to the N2O production in soils. Currently, no contribution from biological N2 fixation in legume pastures is included in the national N2O inventories, partly because of uncertainties in quantifying the N2 fixation in the pastures (Mosier et al., 1998). According to the guidelines issued by The Intergovernmental Panel on Climate Change (IPCC), inventories for N2O emissions from agricultural soils should be based on the assumption that 1.25 % of added N is emitted as N2O (IPCC, 1997). The... |
Tipo: Conference paper, poster, etc. |
Palavras-chave: Nutrient turnover; Pasture and forage crops; Air and water emissions. |
Ano: 2004 |
URL: http://orgprints.org/4147/1/4147.pdf |
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Thyme, Mette; Ambus, Per. |
In organic dairy farming, a major N input to the plant-soil system comes from biological N2 fixation by pasture legumes, but knowledge is sparse on how much of the fixed N2 is lost from the pastures as N2O. Nitrifying and denitrifying bacteria are the main contributors to the N2O production in soils. Currently, no contribution from biological N2 fixation in legume pastures is included in the national N2O inventories, partly because of uncertainties in quantifying the N2 fixation in the pastures (Mosier et al., 1998). According to the guidelines issued by The Intergovernmental Panel on Climate Change (IPCC), inventories for N2O emissions from agricultural soils should be based on the assumption that 1.25 % of added N is emitted as N2O (IPCC, 1997). The... |
Tipo: Conference paper, poster, etc. |
Palavras-chave: Nutrient turnover; Pasture and forage crops; Air and water emissions. |
Ano: 2003 |
URL: http://orgprints.org/1464/1/Poster_Mette_Thyme.pdf |
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Registros recuperados: 44 | |
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