| 1. |
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| 2. |
- Klemedtsson, Åsa Kasimir, 1956, et al.
(författare)
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Low nitrous oxide emission from organic management results in efficient production
- 2012
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Ingår i: Planet under Pressure, new knowledge towards solutions, Poster session 2.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- We compare nitrous oxide (N2O) emission due to organic and integrated conventional farming systems on a research farm "Logården" in south-west Sweden. The soil is characterized by an average clay content of 40%. Both systems have 7 year crop rotations since 1991. Faba beans and spring wheat crops in each management system are compared. The faba bean crops did not receive any nitrogen addition. The organic fields were weeded by hoe while the integrated fields had an under-sown catch crop. Spring wheat followed the next year after the beans, where both managements had a green manure crop under-sown. Fertiliser is only given to the conventional field, 110 kg N ha-1. N2O emission rate was measured by manual chambers during two years. Gas samples were collected every second week and more frequent during freeze/thaw events and at management occasions. Integrated beans had significantly higher emissions (2.3 kg N2O-N ha-1) than the organic. The organic wheat had the significantly lowest average N2O emission (0.2 kg N2O-N ha-1) one year out of two The overall emission is governed by very few occasions of high emissions, mainly in spring and autumn but not specifically following fertiliser addition. We try to explain the causal factors. Yield-scaled N2O emission (emitted N2O-N per harvested N) was found low for both management systems producing wheat but only for the organic faba beans, all having ca 10 g N2O-N kg-1 harvested N, which was twice as high for the integrated beans. Based on our results we discuss options for sustainable and productive agricultural management characterised by low emissions.
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| 3. |
- Koskinen, Cecilia, et al.
(författare)
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Lack of CD47 impairs bone cell differentiation and results in an osteopenic phenotype in vivo due to impaired signal regulatory protein α (SIRPα) signaling
- 2013
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Ingår i: Journal of Biological Chemistry. - 0021-9258 .- 1083-351X. ; 288:41, s. 29333-29344
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Tidskriftsartikel (refereegranskat)abstract
- Here, we investigated whether the cell surface glycoprotein CD47 was required for normal formation of osteoblasts and osteoclasts and to maintain normal bone formation activity in vitro and in vivo. In parathyroid hormone or 1α,25(OH)2-vitamin D3 (D3)-stimulated bone marrow cultures (BMC) from CD47(-/-) mice, we found a strongly reduced formation of multinuclear tartrate-resistant acid phosphatase (TRAP)(+) osteoclasts, associated with reduced expression of osteoclastogenic genes (nfatc1, Oscar, Trap/Acp, ctr, catK, and dc-stamp). The production of M-CSF and RANKL (receptor activator of nuclear factor κβ ligand) was reduced in CD47(-/-) BMC, as compared with CD47(+/+) BMC. The stromal cell phenotype in CD47(-/-) BMC involved a blunted expression of the osteoblast-associated genes osterix, Alp/Akp1, and α-1-collagen, and reduced mineral deposition, as compared with that in CD47(+/+) BMC. CD47 is a ligand for SIRPα (signal regulatory protein α), which showed strongly reduced tyrosine phosphorylation in CD47(-/-) bone marrow stromal cells. In addition, stromal cells lacking the signaling SIRPα cytoplasmic domain also had a defect in osteogenic differentiation, and both CD47(-/-) and non-signaling SIRPα mutant stromal cells showed a markedly reduced ability to support osteoclastogenesis in wild-type bone marrow macrophages, demonstrating that CD47-induced SIRPα signaling is critical for stromal cell support of osteoclast formation. In vivo, femoral bones of 18- or 28-week-old CD47(-/-) mice showed significantly reduced osteoclast and osteoblast numbers and exhibited an osteopenic bone phenotype. In conclusion, lack of CD47 strongly impairs SIRPα-dependent osteoblast differentiation, deteriorate bone formation, and cause reduced formation of osteoclasts.
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| 4. |
- Myrbeck, Åsa, et al.
(författare)
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Changes in N leaching and crop production as a result of measures to reduce N losses to water in a 6-yr crop rotation
- 2014
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Ingår i: Soil Use and Management. - : Wiley. - 0266-0032 .- 1475-2743. ; 30, s. 219-230
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Tidskriftsartikel (refereegranskat)abstract
- The effects of various measures introduced to increase nitrogen (N) use efficiency and reduce N losses to water in a six-year crop rotation (winter wheat, spring barley, , , green manure, winter wheat, spring barley, spring oilseed rape) were examined with respect to N leaching, soil mineral N (SMN) accumulation and grain yield. An N use efficient system (NUE) with delayed tillage until late autumn and spring, direct drilling of winter wheat, earlier sowing of winter and spring crops and use of a catch crop in winter wheat was compared with a conventional system (CON) in a field experiment with six separately tile-drained plots in south-western Sweden during the period 1999-2011 (two crop rotation cycles). Total leaching of NO3-N from the NUE system was significantly 46% and 33% lower than in the CON system during the first and second crop rotation cycle, respectively, with the most pronounced differences apparently related to management strategies for winter wheat. Differences in NO3-N leaching largely reflected differences in SMN during autumn and winter. There was a tendency for lower yields in the NUE system, probably due to problems with couch-grass. Overall, the measures for conserving N, when frequently used within a crop rotation, effectively reduced NO3 concentrations in drainage water and NO3-N leaching losses, without severely affecting yield.
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| 5. |
- Myrbeck, Åsa, et al.
(författare)
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Effects of autumn tillage of clay soil on mineral N content, spring cereal yield and soil structure over time
- 2012
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Ingår i: European Journal of Agronomy. - : Elsevier BV. - 1161-0301 .- 1873-7331. ; 37, s. 96-104
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Tidskriftsartikel (refereegranskat)abstract
- Autumn tillage strategies designed to reduce leaching losses of nitrogen (N) from arable fields were examined on a medium clay soil (approx. 40% clay) in terms of their effects on accumulation of soil mineral N (SMN) during autumn and winter, crop N uptake, grain yield (spring-sown cereals) and soil structure over the long term (1997-2004). Tillage strategies included mouldboard ploughing (20-25 cm depth) and stubble cultivation (10-12 cm depth) in different combinations and timing, together with different options for straw management and catch crops. Postponing mouldboard ploughing from early September to early November significantly decreased SMN content during autumn and winter, although levels were generally low in all treatments. On average, the soil profile down to 90 cm depth contained 30 kg N ha(-1) in November and 27 kg N ha(-1) in December with early mouldboard ploughing, while the corresponding figures for late mouldboard ploughing were 16 and 21 kg N ha(-1). Stubble cultivation stimulated N mineralisation but the increase in SMN from tillage in September to November was only 3 kg ha(-1) after stubble cultivation, compared with 8 kg ha(-1) after mouldboard ploughing. Stubble cultivation before late mouldboard ploughing resulted in 6 kg ha(-1) higher SMN during autumn than late ploughing without preceding cultivation. Postponement of mouldboard ploughing significantly decreased grain yield by on average 11% and this negative effect accumulated over time. A catch crop compared with no catch crop reduced SMN during autumn and winter by 3-5 kg ha(-1) and had no significant yield effect. Effects of straw incorporation were small and could not be significantly proven either for SMN or yield. Transport of SMN to deeper layers was generally limited and SMN did not decrease during winter, indicating a minor impact of tillage time on N leaching risk. No significant changes in soil physical parameters were detected, but the results indicated poorer soil structure after tillage in late autumn compared with early autumn in terms of higher soil bulk density, lower aggregate stability in water, and lower infiltration rate. Overall, considering the short-term and long-term negative effects on yield and possibly soil structure, the benefit of delaying tillage seems small on this clay soil. (C) 2011 Elsevier B.V. All rights reserved.
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| 6. |
- Myrbeck, Åsa, et al.
(författare)
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Establishment of winter wheat-Strategies for reducing the risk of nitrogen leaching in a cool-temperate region
- 2012
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Ingår i: Soil and Tillage Research. - : Elsevier BV. - 0167-1987 .- 1879-3444. ; 120, s. 25-31
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Tidskriftsartikel (refereegranskat)abstract
- Different strategies for establishment of winter wheat were studied in six field experiments in southern and south-western Sweden examining accumulation of soil mineral nitrogen (SMN) during autumn and winter. Conventional tillage (CT), reduced tillage (RT) and non-tillage (NT) and early (1) and late (2) time of tillage were tested in combination with early (1) and late (2) sowing (S) times, including different time intervals between tillage and sowing. Amount of SIVIN in November followed the treatment order: CT1 Si < RT1 S1 < NT S1 < CT2 S2 < RT2 S2 < NT S2 < RT1 S2 < CT1 S2 in field trials where glyphosate was applied early in autumn and the order: CT1 S1 < RT1 S1 < NT S1 < RT2 S2 < CT2 S2 < RT1 S2 < CT1 S2 in field trials where no glyphosate was applied. Autumn SMN was reduced by 14-24 kg ha(-1) when sowing was carried out immediately after early tillage compared with 3-4 weeks after tillage. This could not be attributed to a direct effect of tillage on N mineralisation, but to differences in crop and weed uptake of N. With the same time interval between tillage and sowing, in general there were no significant differences between tillage methods. Sowing time did not affect winter wheat yield. The results demonstrated the importance of a well-established winter crop and of the combined timing of tillage, sowing date and application of glyphosate or other herbicides in reducing nitrogen leaching. (C) 2012 Elsevier B.V. All rights reserved.
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| 7. |
- Nylinder, Josefine, 1974, et al.
(författare)
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Modelling uncertainty for nitrate leaching and nitrous oxide emissions based on a Swedish field experiment with organic crop rotation
- 2011
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Ingår i: Agriculture, Ecosystems & Environment. - : Elsevier BV. - 0167-8809 .- 1873-2305. ; 141:1-2, s. 167-183
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Tidskriftsartikel (refereegranskat)abstract
- High uncertainties are common in detailed quantification of the N budget of agricultural cropping systems. The process-based CoupModel, integrated with the parameter calibration method known as Generalized likelihood uncertainty estimation (GLUE), was used here to define parameter values and estimate an N budget based on experimental data from an organic farming experiment in south-west Sweden. Data on nitrate (NO3-) leaching and nitrous oxide (N2O) emissions were used as a basis for quantifying N budget pools. A complete N budget with uncertainties associated with the different components of the N cycle compartments for two different fields (B2 and B4) is presented. Simulated N2O emissions contributed 1-2% of total N output, which corresponded to 7% and 8.7% of total N leaching for B2 and B4, respectively. Measured N2O emissions contributed 3.5% and 10.3% of total N leaching from B2 and B4, respectively. Simulated N inputs (deposition, plant N fixation and fertilisation) and outputs (emissions, leaching and harvest) showed a relatively small range of uncertainty, while the differences in N storage in the soil exhibited a larger range of uncertainty. One-fifth of the GLUE-calibrated parameters had a significant impact on simulated NO3- leaching and/or N2O emissions data. Emissions of N2O were strongly associated with the nitrification process. The high degree of equifinality indicated that a simpler model could be calibrated to the same field data.
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| 8. |
- Picha Edwardsson, Malin, 1970-
(författare)
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Media processes for content production : Studies of structures and climate impacts
- 2012
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The business environment in which media companies exist today is rapidly changing. Many media companies are in the process of positioning themselves to this ongoing change and to finding their place in the new media landscape. A process of change creates an opportunity to optimize work processes on different levels. In order to meet these opportunities, as well as being proactive when it comes to environmental performance, we need to understand the current structures of media companies, for example when it comes to work processes.The aim of this study is to identify and analyze the process structures and the potential climate impact of the content production of three different media companies in Sweden: a local newspaper, a monthly magazine and a local television station. The overall research questions of this thesis are:• What are the major editorial processes at media companies and how can the workflows be visualized, in order for us to discover how the processes can be optimized and how this in turn may affect the environmental impact?• How are the results of the process analysis related to a general assessment of the carbon footprint of the content production, in order for us to identify the major reasons for this potential climate change impact and opportunities for change?The research methods used were semi-structured interviews and carbon footprint assessment. The research results suggest that in general terms, newspapers and magazines spend a considerable amount of working time producing content, and content production is the single most important reason for travelling at the three media companies studied. Travel is also done by management to a high degree in all three case studies, mostly to different kinds of business meetings. Planning is another work activity that takes up a considerable amount of time when looking at the total time spent at work. Computers are to a high degree used when planning, but more advanced computer programmes or tools could be recommended to expand the planning possibilities further, thereby saving time and money for the media company.The results of the life cycle assessments indicate that the major reasons for potential climate change impact are travel – both work-related business travel and trips to and from work – electronic equipment, and electricity use. The research results suggest that in order to reduce potential environmental impact from travel, media management should look into technical solutions for meetings at a distance, car-pooling or increasing the use of public transportation. Furthermore, new technical solutions have a potential to lower the costs of the content production processes and streamline work processes in general. With a conscious effort by management, new technology could also be beneficial for the overall environmental impact of the media company. The media companies could for example consider the environmental performance to a higher degree when buying new electronic devices, such as computers. Finally, the media companies could look over their electricity use and make an attempt to reduce their electricity use, as well as making active choices for environmentally friendly alternatives when choosing electricity supplier.
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| 9. |
- Rees, R. M., et al.
(författare)
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Nitrous oxide emissions from European agriculture; an analysis of variability and drivers of emissions from field experiments
- 2012
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Ingår i: Biogeosciences Discussions. - : Copernicus GmbH. - 1810-6277. ; 9:7, s. 9259-9288
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Tidskriftsartikel (refereegranskat)abstract
- Nitrous oxide emissions from a network of agricultural experiments in Europe and Zimbabwe were used to explore the relative importance of site and management controls of emissions. At each site, a selection of management interventions were compared 5 within replicated experimental designs in plot based experiments. Arable experiments were conducted at Beano in Italy, El Encin in Spain, Foulum in Denmark, Logården in Sweden, Maulde in Belgium, Paulinenaue in Germany, Harare in Zimbabwe and Tulloch in the UK. Grassland experiments were conducted at Crichton, Nafferton and Peaknaze in the UK, Gödöllö in Hungary, Rzecin in Poland, Zarnekow in Germany and 10 Theix in France. Nitrous oxide emissions were measured at each site over a period of at least two years using static chambers. Emissions varied widely between sites and as a result of manipulation treatments. Average site emissions (throughout the study period) varied between 0.04 and 21.21 kg N2O-N ha−1 yr−1, with the largest fluxes and variability associated with the grassland sites. Total nitrogen addition was found to be 15 the single most important determinant of emissions, accounting for 15% of the variance (using linear regression) in the data from the arable sites (p < 0.0001), and 77% in the grassland sites. The annual emissions from arable sites were significantly greater than those that would be predicted by IPCC default emission factors. Variability in N2O within sites that occurred as a result of manipulation treatments was greater than that 20 resulting from site to site and year to year variation, highlighting the importance of management interventions in contributing to greenhouse gas mitigation.
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| 10. |
- Rees, R. M., et al.
(författare)
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Nitrous oxide emissions from European agriculture - an analysis of variability and drivers of emissions from field experiments
- 2013
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Ingår i: Biogeosciences. - : Copernicus GmbH. - 1726-4170 .- 1726-4189. ; 10:4, s. 2671-2682
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Tidskriftsartikel (refereegranskat)abstract
- Nitrous oxide emissions from a network of agricultural experiments in Europe and Zimbabwe were used to explore the relative importance of site and management controls of emissions. At each site, a selection of management interventions were compared within replicated experimental designs in plot based experiments. Arable experiments were conducted at Beano in Italy, El Encin in Spain, Foulum in Denmark, Logården in Sweden, Maulde in Belgium, Paulinenaue in Germany, Harare in Zimbabwe and Tulloch in the UK. Grassland experiments were conducted at Crichton, Nafferton and Peaknaze in the UK, Gödöllö in Hungary, Rzecin in Poland, Zarnekow in Germany and Theix in France. Nitrous oxide emissions were measured at each site over a period of at least two years using static chambers. Emissions varied widely between sites and as a result of manipulation treatments. Average site emissions (throughout the study period) varied between 0.04 and 21.21 kg N2O-N ha−1 yr−1, with the largest fluxes and variability associated with the grassland sites. Total nitrogen addition was found to be the single most important determinant of emissions, accounting for 15% of the variance (using linear regression) in the data from the arable sites (p < 0.0001), and 77% in the grassland sites. The annual emissions from arable sites were significantly greater than those that would be predicted by IPCC default emission factors. Variability in N2O within sites that occurred as a result of manipulation treatments was greater than that resulting from site to site and year to year variation, highlighting the importance of management interventions in contributing to greenhouse gas mitigation.
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