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Registros recuperados: 27
Primeira ... 12 ... Última
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Afgrøderester og sædskifte har stor betydning for udledning af lattergas Organic Eprints
Petersen, Søren O.; Schjønning, P.; Ambus, Per.
Lattergas udgør en del af det atmosfæriske tab af kvælstof fra dyrkningsjorden. Målt i kg kvælstof er mængderne små, men fordi lattergas er en meget kraftig drivhusgas, er gassens betydning for landbrugets samlede udledninger stor.
Tipo: Newspaper or magazine article Palavras-chave: Cereals; Pulses and oilseeds Air and water emissions Farm nutrient management.
Ano: 2011 URL: http://orgprints.org/22013/1/22013.pdf
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Catch Crop Residues Stimulate N2O Emissions During Spring, Without Affecting the Genetic Potential for Nitrite and N2O Reduction Organic Eprints
Duan, Yun-Feng; Hallin, Sara; Jones, Christopher M.; Priemé, Anders; Labouriau, Rodrigo; Petersen, Søren O..
Organic agriculture depends on recycling of N to sustain crop production, and the use of catch crops to prevent leaching losses during winter is part of this strategy. The finding in this study, that catch crop residues were a more consistent source of nitrous oxide emissions in spring than synthetic fertiliser, indicates catch crop residue decomposition may contribute negatively to the climate impact of the farming system. Management practices are needed that reduce the potential for denitrification, which is the main source of nitrous oxide. Possible strategies include cultivation to promote aerobic rather than anaerobic degradation, and timing of manure application to avoid that mineral N from manure accumulates during residue decomposition....
Tipo: Journal paper Palavras-chave: Crop combinations and interactions; Soil biology; Nutrient turnover; Air and water emissions.
Ano: 2018 URL: http://orgprints.org/36654/1/fmicb_09_02629.pdf
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Developments in greenhouse gas emissions and net energy use in Danish agriculture - How to achieve substantial CO2 reductions? Organic Eprints
Dalgaard, Tommy; Olesen, Jørgen E.; Petersen, B.M.; Petersen, Søren O.; Jørgensen, Uffe; Kristensen, Troels; Hutchings, Nicholas J.; Gyldenkerne, Steen; Hermansen, J.E..
Greenhouse gas (GHG) emissions from agriculture are a significant contributor to total Danish emissions. Consequently, much effort is currently given to the exploration of potential strategies to reduce agricultural emissions. This paper presents results from a study estimating agricultural GHG emissions in the form of methane, nitrous oxide and carbon dioxide (including carbon sources and sinks, and the impact of energy consumption/bioenergy production) from Danish agriculture in the years 1990-2010. An analysis of possible measures to reduce the GHG emissions indicated that a 50-70% reduction of agricultural emissions by 2050 relative to 1990 is achievable, including mitigation measures in relation to the handling of manure and fertilisers,...
Tipo: Journal paper Palavras-chave: Nutrient turnover; Air and water emissions; Buildings and machinery; Landscape and recreation; Farm nutrient management.
Ano: 2011 URL: http://orgprints.org/19044/4/19044.pdf
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Dynamics of a pasture soil microbial community after deposition of cattle urine amended with [13C]urea Organic Eprints
Petersen, Søren O.; Roslev, Peter; Bol, Roland.
Within grazed pastures, urine patches are hot-spots of nitrogen turnover since dietary N surpluses are excreted mainly as urea in the urine. This short-term experiment investigated 13C uptake in microbial lipids after simulated deposition of cattle urine at 10.0 and 17.1 g urea-C m-2. Confined field plots without or with cattle urine amendment were sampled after 4 and 14 days, and soil from 0-5 and 10-20 cm depth was analyzed for content and composition of phospholipid fatty acids (PLFAs), and for the distribution of urea-derived 13C among individual PLFAs. Carbon dioxide emissions were quantified and the contributions derived from urea assessed. Initial changes in PLFA composition were greater at the lower level of urea, as revealed by a principal...
Tipo: Journal paper Palavras-chave: Soil biology.
Ano: 2004 URL: http://orgprints.org/4061/1/4061.pdf
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Effects of C and N availability and soil-water potential interactions on N2O evolution and PLFA composition Organic Eprints
Andersen, Astrid J.; Petersen, Søren O..
Mitigation of agricultural N2O emissions via management requires quantitative information about the regulation of the underlying processes. In this laboratory study. short-term evolution of N2O from repacked soil was determined using an arable sandy loam soil adjusted to three water potentials (-15,-30 or -100 hPa) that were reached by adjustment of partly air-dried soil with nutrient solutions or water; a water retention curve of repacked soil had been determined prior to the incubation experiment. The amendments included a control treatment receiving water (CTL), and aqueous solutions of carbon in the form of glucose (C). ammonium sulfate (N), or both (CN). Rates Of CO2 and N2O evolution were followed during 14 days. Soil inorganic N and phospholipid...
Tipo: Journal paper Palavras-chave: Environmental aspects; Soil.
Ano: 2009 URL: http://orgprints.org/16097/2/16097.pdf
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Effects of contrasting catch crops on nitrogen availability and nitrous oxide emissions in an organic cropping system Organic Eprints
Li, Xiaoxi; Petersen, Søren O.; Sørensen, Peter; Olesen, Jørgen E..
Abstract Legume-based catch crops (LBCCs) may act as an important source of nitrogen (N) in organic crop rotations because of biological N fixation. However, the potential risk of high nitrous oxide (N2O) emissions needs to be taken into account when including LBCCs in crop rotations. Here, we report the results from a one-year field experiment, which investigated N availability and N2O emissions as affected by three LBCCs, i.e., red clover (CL), red clover–ryegrass mixture (GC) and winter vetch (WV), two non-LBCCs, i.e., perennial ryegrass (GR) and fodder radish (FR), and a control (CO) without catch crops. The effect of two catch crop management strategies was also tested: autumn harvest of the catch crop versus incorporation of whole-crop residues by...
Tipo: Journal paper Palavras-chave: Cereals; Pulses and oilseeds Nutrient turnover Air and water emissions Farm nutrient management.
Ano: 2015 URL: http://orgprints.org/28131/2/28131.pdf
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Effects of green manure storage and incorporation methods on greenhouse gas fluxes and N mineralization after soil application Organic Eprints
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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Effects of green manure storage and incorporation methods on nitrogen release and N2O emissions after soil application Organic Eprints
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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Effects of green manure storage and incorporation methods on nitrogen release and N2O emissions after soil application Organic Eprints
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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Effects of green manure storage and incorporation methods on nitrogen release and N2O emissions after soil application Organic Eprints
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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Effects of green manure storage and incorporation methods on nitrogen release and N2O emissions after soil application Organic Eprints
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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Evidence for denitrification as main source of N2O emission from residue-amended soil Organic Eprints
Li, Xiaoxi; Sørensen, Peter; Olesen, Jørgen E.; Petersen, Søren O..
Catch crops, especially leguminous catch crops, may increase crop nitrogen (N) supply and decrease environmental impacts in cropping systems, but they may also stimulate nitrous oxide (N2O) emissions following spring incorporation. In this 28-day laboratory incubation study, we examined the carbon (C) and N dynamics and N2O evolution after simulated incorporation of residues from three catch crop species into a loamy sand soil, with variable soil moisture (40, 50 or 60% water-filled pore space (WFPS)). The catch crops include two leguminous (red clover and winter vetch) and one non-leguminous species (ryegrass). Plant material was placed in a discrete layer surrounded by soil in which the nitrate (NO3-) pool was enriched with 15N to distinguish N2O derived...
Tipo: Journal paper Palavras-chave: Pasture and forage crops; Crop combinations and interactions; Nutrient turnover; Air and water emissions; Farm nutrient management.
Ano: 2015 URL: http://orgprints.org/30111/1/LXX3-2016%20SBB%20vol%2092%20p153-160.pdf
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Flow of nutrients and climate relevant gases in experimental rotations on three soil types Organic Eprints
Petersen, Søren O..
Within organic farming there is a continued effort to close nutrient cycles in order to improve nutrient use efficiency for crop production while also minimizing environmental impacts. In Denmark a long-term crop rotation experiment on three soil types, i.e., Jyndevad (4.5% clay, 2.0% C), Foulum (8.8% clay, 3.8% C) and Flakkebjerg (15.5% clay, 1.7% C), provides a platform for studies of agronomic and environmental aspects of organic farming. Selected results from investigations at these sites are presented. In 2007 and 2008 one study determined soil microbial biomass N and mineralizable N on all three locations during the growing season in four selected rotations, three organic and one conventional; the objective was to evaluate the role of soil...
Tipo: Conference paper, poster, etc. Palavras-chave: Farming Systems; Air and water emissions; Denmark.
Ano: 2009 URL: http://orgprints.org/19468/4/19468.pdf
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Klimaeffekten af mobil grøngødning Organic Eprints
Petersen, Søren O.; Sørensen, Peter.
Klimabelastning bør indgå i vurderingen af dyrkningssystemers bæredygtighed. Vi undersøgte udledningen af drivhusgasser under opbevaring og efter udbringning af gødningsprodukter til økologiske sædskifter: Afhøstet kløvergræs som blev ensileret eller komposteret, og plantebiomasse som blev afgasset sammen med gylle. Både afgasset gylle og ensilage af kløvergræs viste positive resultater mht. merudbytte og klimaeffekt.
Tipo: Newspaper or magazine article Palavras-chave: Dairy cattle; Farming Systems; Composting and manuring; Farm nutrient management.
Ano: 2014 URL: http://orgprints.org/25342/6/25342.pdf
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Kløvergræs ensilage og kompost som grøngødning Organic Eprints
Carter, Mette S.; Ambus, Per; Petersen, Søren O.; Sørensen, Peter.
En ny strategi kan måske forbedre udnyttelsen af det kvælstof, som fikseres af kløverplanter i økologisk planteavl. Vores studie viste en større frigivelse af kvælstof fra ensileret kløvergræs end fra kompost af kløvergræs iblandet halm. Samtidig fandt vi, at indarbejdning af grøngødning ved harvning frem for pløjning reducerede udledningen af den stærke drivhusgas, lattergas.
Tipo: Newspaper or magazine article Palavras-chave: Nutrient turnover; Air and water emissions.
Ano: 2013 URL: http://orgprints.org/24959/14/24959.pdf
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Kvælstofdynamik i økologiske sædskifter Organic Eprints
Petersen, Søren O..
Jordens indhold af "aktivt" kvælstof påvirkes af sædskiftet. Kendskab til mængder og dynamik kan fremme selvforsyningen på økologiske bedrifter.
Tipo: Newspaper or magazine article Palavras-chave: Farming Systems; Soil.
Ano: 2009 URL: http://orgprints.org/16098/1/16098.pdf
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Long-term effects of cropping system on N2O emission potential Organic Eprints
Petersen, Søren O.; Ambus, Per; Elsgaard, Lars; Schjønning, P.; Olesen, Jørgen E..
The potential for N2O emissions outside the main growing season may be influenced by long-term effects of cropping system. This was investigated by collecting intact soil cores (100 cm3, 0-4 cm depth) under winter wheat in three organic cropping systems and a conventional reference within a long-term crop rotation experiment. Average annual inputs of C in crop residues and manure ranged from 1.7 to 3.3 Mg ha-1. A simulated freeze-thaw cycle resulted in a flush of CO2 during the first 48 h, which could be mainly from microbial sources. Other samples were adjusted to approximately –10, -30 or –100 hPa and amended with excess 15NO3- prior to freezing and thawing. Denitrification was the main source of N2O during a 72-h incubation at 22C, as judged from N2O...
Tipo: Journal paper Palavras-chave: Soil biology; Air and water emissions; Farm nutrient management.
Ano: 2013 URL: http://orgprints.org/22014/1/22014.pdf
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Nitrogen mineralization and greenhouse gas emissions after soil incorporation of ensiled and composted grass-clover as green manure Organic Eprints
Carter, Mette S.; Sørensen, Peter; Petersen, Søren O.; Ambus, Per.
This 3-month incubation study showed that ensiled grass-clover was a better nitrogen (N) source than a composted grass-clover and straw mix (grass-clover:straw, 4:1, w:w), owing to the high content of labile compounds compared to the more degraded compost. Our study also indicated that emissions of the strong greenhouse gas nitrous oxide (N2O) can be reduced by incorporating green manure using harrowing instead of ploughing. The silage-derived N release by the end of the incubation was equivalent to 38-42 kg N ha-1, which corresponded to one third of the N applied in silage, with no difference between ploughing and harrowing. In contrast, no net release of mineral N was detected from the composted grass-clover.
Tipo: Conference paper, poster, etc. Palavras-chave: Composting and manuring; Nutrient turnover; Air and water emissions.
Ano: 2013 URL: http://orgprints.org/24520/1/24520.pdf
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Nitrous oxide emissions and grassland management Organic Eprints
Petersen, Søren O..
Nitrous oxide emissions and grassland management Søren O. Petersen, Danish Institute of Agricultural Sciences, Dept. Crop Physiology and Soil Science, Denmark Carbon storage in grasslands is a potentially important mitigation option in support of the Kyoto process. However, the effect of C sequestration by pastures depends significantly on the fate of N inputs via animal deposits, atmospheric N2 fixation or inorganic fertilizers, since N2O derived from N turnover can partly or completely off-set the removal of atmospheric CO2. Urine spots have been identified as strong sources of N2O, but the quantification of N2O emissions from grazed pastures is complicated by temporal and spatial variability, and by limited understanding of the interactions...
Tipo: Other Palavras-chave: Air and water emissions.
Ano: 2001 URL: http://orgprints.org/121/1/Dublin_poster_30%2D3%2D2001.ppt
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Nitrous oxide emissions from arable soil: Effects of crop rotation, tillage and manure management Organic Eprints
Petersen, Søren O..
Soil carbon storage and nitrous oxide (N2O) emissions are both important for the greenhouse gas balance of agricultural soil, but difficult to verify under field conditions due to high spatial and temporal variability. Carbon stock changes are particularly elusive because they occur over decades, and future climate or management changes may revert current trends. Emissions of N2O from arable soil are derived mainly from the short-term (<1 yr) turnover of crop residues, fertilizers and manure, which indicates that mitigation options may be found with a better understanding of management effects on soil C and N cycling and N2O emissions. This presentation will describe N2O studies within long-term crop rotation experiments that allow side-by-side...
Tipo: Conference paper, poster, etc. Palavras-chave: Nutrient turnover; Soil tillage; Air and water emissions; Farm nutrient management.
Ano: 2011 URL: http://orgprints.org/22016/1/22016.PDF
Registros recuperados: 27
Primeira ... 12 ... Última
 

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