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| Registros recuperados: 27 | |
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| 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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| Petersen, Søren O.; Stamatiadis, Stamatis; Christofides, Calliopi. |
| Nitrogen excreted by cattle during grazing is a significant source of atmospheric nitrous oxide (N2O). The regulation of N2O emissions is not well understood, but may vary with urine composition and soil conditions. This laboratory study was undertaken to describe short-term effects on N2O emissions and soil conditions, including microbial dynamics, of urea amendment at two different rates (22 and 43 g N m-2). The lower urea concentration was also combined with an elevated soil NO3- concentration. Urea solutions labelled with 25 atom% 15N were added to the surface of repacked pasture soil cores and incubated for 1, 3, 6 or 9 days under constant conditions (60% WFPS, 14°C). Soil inorganic N (NH4+, NO2- and NO3-), pH, electrical conductivity and dissolved... |
| Tipo: Journal paper |
Palavras-chave: Air and water emissions. |
| Ano: 2004 |
URL: http://orgprints.org/4062/1/4062.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.; 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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| 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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| 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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| Petersen, Søren O.; Schjønning, P.; Olesen, Jørgen E.; Christensen, S.; Christensen, B.T.. |
| In organic cropping systems, legumes, cover crops, residue incorporation, and manure application are used to maintain soil fertility, but the contributions of these management practices to soil nitrogen (N) supply remain obscure. We examined potential sources of N for winter wheat (Triticum aestivum L.) in four experimental cropping systems established in 1997 on three soil types. Three of the four systems were under organic management. Topsoil N, depth of the A horizon, and cumulated inputs of N since 1997 were determined at plot level. Labile soil N pools (mineral N, potentially mineralizable N [PMN], microbial biomass N [MBN]) were monitored during two growth periods; at one site, biomass C/N ratios were also determined. Soil for labile N analysis was... |
| Tipo: Journal paper |
Palavras-chave: Crop combinations and interactions; Soil biology; Nutrient turnover; Farm nutrient management. |
| Ano: 2013 |
URL: http://orgprints.org/22015/7/22015.pdf |
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| Petersen, Søren O.; Simek, Miloslav; Stamatiadis, Stamatis; Yamulki, Sirwan. |
| Traditionally, dairy cattle spend a substantial part of the year on pastures. For organic farming within EU it is specified that ”all mammals must have access to pasturage or an open-air exercise area” which they must be able to use whenever ”weather conditions and the state of the ground permits” (Council Regulation [EEC] No 2092/91 ). Dairy production systems are characterized by a considerable N surplus, and N deposited during grazing represents a significant risk for environmental losses, including N2O emissions. Excess N is excreted mainly in the urine, the composition of which is influenced by factors such as lactation stage, sward quality and intake of supplements. Resulting N concentrations in urine patches can range from 20 to 80 g N m-2, and... |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Dairy cattle. |
| Ano: 2004 |
URL: http://orgprints.org/4079/1/4079.pdf |
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| 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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| 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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| 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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| 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 |
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| 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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| Petersen, Søren O.; Bol, Roland; Dittert, Klaus; Christofides, Calliopi; Roslev, Peter; Hansen, Martin N.. |
| Managed grasslands can accumulate soil organic carbon and thereby remove CO2 from the atmosphere. When grazed, however, the interaction between N inputs (fertilization, feeding, N fixation) and excretal returns can lead to sward deterioration and elevated emissions of N2O in urine patches. Both effects may reduce the positive effect of carbon storage on the greenhouse gas balance. A field plot study was carried out between 19 September and 4 October 2001, in which cattle urine amended with 13C- and 15N-labelled urea was added to a sandy loam pasture. Two levels of urea, corresponding to 23.3 and 39.8 g urea-N m-2, were compared with an unamended control. Ammonia losses corresponded to 14 and 12% of the urea-N applied in the low (UL) and high (UH) urea... |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Air and water emissions. |
| Ano: 2004 |
URL: http://orgprints.org/2906/1/Ghent_presentation_020604.ppt |
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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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| Bol, Roland; Petersen, Søren O.; Christofides, Calliopi; Dittert, Klaus; Hansen, Martin Nørregaard. |
| Urine patches are significant hot-spots of C and N transformations. To investigate the effects of urine composition on C and N turnover and gaseous emissions from a Danish pasture soil, a field plot study was carried out in September 2001. Cattle urine was amended with two levels of 13C- and 15N-labeled urea, corresponding to 5.58 and 9.54 g urea-N l-1, to reflect two levels of protein intake. Urine was then added to a sandy-loam pasture soil equivalent to a rate of 23.3 or 39.8 g urea-N m-2. Pools and isotopic labeling of nitrous oxide (N2O) and CO2 emissions, extractable urea, ammonium (NH4+), and nitrate (NO3-), and plant uptake were monitored during a 14 d period, while ammonia (NH3) losses were estimated in separate plots amended with unlabeled urine.... |
| Tipo: Journal paper |
Palavras-chave: Air and water emissions. |
| Ano: 2004 |
URL: http://orgprints.org/4060/1/4060.pdf |
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| Registros recuperados: 27 | |
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