859 research outputs found

    Can organic farming help to reduce national energy consumption and emissions of greenhouse gasses in Denmark?

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    Methods to investigate whether organic farming might help toreduce energy consumption and greenhouse gas emissions areneeded. The aim of this study is for the first to present anupscaling procedure, where an existing farm level energyconsumption model, in combination with the IntergovernmentalPanel on Climate Change’s guidelines, is used to calculateagricultural energy consumption and greenhouse gas emissionson the national level. Secondly, this procedure is used to simulatescenarios for conversion to organic farming in Denmark.Three scenarios for conversion to organic farming with thepresent crop yield and an expected improved future crop yieldare compared to the 1996-situation in Denmark, whereconventional farming dominates. In all scenarios, fossil energyuse and emissions of the three major agricultural greenhousegases carbon dioxide, methane and nitrous oxide are reduced.The highest reduction in the net energy use (49-51%) is found ina scenario (A) with 100% fodder self-sufficiency and reducedlivestock production, while the lowest reduction (10-16%) isfound in a scenario (C), with the same animal production as in1996. The average energy use per fodder unit in the organic cropproduction (1.4-1.5 MJ/fodder unit) and livestock production(18-24 MJ/livestock unit), was lower than in the 1996-situation(2.5 MJ/fodder unit, and 30 MJ/livestock unit). However, totalproduction was also lower in the organic scenarios, whichfurthermore had different compositions, with lower potentials forfuture bio-energy production

    Can organic farming help to reduce N-losses? Experiences from Denmark

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    This study is in two parts. In the first part, nitrogen N)losses per unit of milk and meat in Danish conventional and organic pig and dairy farming were compared on the basis of farm data. In the second part, organic and conventional dairy farming were compared in detail, using modelling. N-surpluses at different livestock densities, fodder intensities, and soil types were simulated. Finally, simulated N-surpluses were used in national scenarios for conversion to organic dairy farming in Denmark. In Part one, pig farming was found to have a higher N-efficiency than dairy farming. Organic pig production had a lower N-efficiency and a higher N-surplus per kg meat than conventional pig production. The possibilities to reduce N-loss by conversion to organic pig production therefore appear to be poor. Organic dairy farming had a higher N-efficiency and a lower N-surplus per kg milk than conventional dairy farming. Conversion from conventional to organic dairy farming may therefore reduce N-losses. In Part two, a positive correlation between livestock density and N-surplus ha−1 was found for dairy farming. For all simulated livestock densities, fodder feeding intensities and soil types, organic systems showed a lower N-surplus per unit of milk produced than conventional systems. National scenarios for dairy farming showed that the present Danish milk production could be achieved with a 24% lower total N-surplus if converted from intensive conventional farming to extensive organic farming. At the same time, N-surplus ha−1 and N-surplus (tmilk) −1 would be lowered by 50% and 25%respectively. Changing from intensive to extensive conventional dairy farming with a livestock density equal to that in the organic scenario resulted in a reduction in N-surplus ha−1 of 15%. It was concluded that a reduction in total N-loss from agriculture is possible by converting from conventional to organic dairy farming but at the cost of either lower production on the present dairy farm area, or the current production on a substantially larger area

    A model for fossil energy use in Danish agriculture used to compare organic and conventional farming

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    Knowledge about fossil energy use in agricultural systems is needed, because it can improve the understanding of how to reduce the unsustainable use of limited energy resources and the following greenhouse gas emissions. This study describes and validates a model to assess fossil energy use in Danish agriculture; gives an example of how the model can be used to compare organic and conventional farming; and discusses the implications and potentials of using the model to simulate energy use in scenarios of agricultural production. The model is a development of an existing model, which was too coarse to predict measured energy use on Danish farms. The model was validated at the field operational, thecroptype, and the national level, and can supplement the Intergovernmental Panel on Climate Change manual to quantify fossil energy use and subsequent carbon dioxide emissions from agriculture. The model can be used to model energy use as one indicator in a multi-criteria evaluation of sustainability, also including other agroecological and socio-economicindicators. As an example, energy use for eight conventional and organic crop types on loamy, sandy, and irrigated sandy soil was compared. The energy use was generally lower in the organic than in the conventionalsystem, but yields were also lower. Consequently, conventional crop production had the highest energy production, where as organic crop production had the highest energy efficiency. Generally, grain cereals such as wheat have a lower energy use per area than roughage crops such as beets. However, because of higher roughage crop yields per area, energy use per feed unit was higher in the roughage crops. Energy use for both conventional cattle and pig production was found to be higher than that for organic production. With respect to fossil energy use per produced livestock unit, agro-ecosystems producing pigs were in both cases less energy effective than those producing cattle. Fossil energy use for thre escenarios of conversion to organic farming with increasing fodder import was compared to current conventional farming in Denmark.The scenario with the highest fodder import showed the highest energy use per livestock unit produced. In all scenarios, the energy use per unit produced was lower than in the present situation. However, the total Danish crop production was also lower. In conclusion, the model can be used to simulate scenarios, which can add new information to the discussion of future, sustainable agricultural production

    Transition to renewable resources - energy balance comparisons of organic and conventional farming systems and potentials for the mitigation of fossil resource use

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    Today, agriculture and food production has major implications for the use of fossil energy and other resources, and a sustainable development implies transition towards new systems, based on renewable resources. The reduction of external inputs to the farm through efficient management of materials and energy is a central part of the organic principles (IFOAM 2013), and in most countries standards are implemented in the form of nationally adapted, organic farming regulations, with significant implications for the potential energy and matter flows in- and out of the agricultural systems, and thereby the energy balance and the use of renewable resources. Consequently, it is important to develop new and more resource efficient production systems mitigating organic farming’s reliance on fossil resources, and to compare different pathways towards reduced resource consumption in agriculture

    Can on-farm bioenergy production make organic farming more sustainable? - A model for energy balance, nitrogen losses, and green house gas emissions in a 1000 ha energy catchment with organic dairy farming and integrated bioenergy production

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    Can biogas and bioethanol production make organic farming more sustainable? - Results from a model for the fossil energy balance, Nitrogen losses, and greenhouse gas emissions in a 1000 ha energy catchment with organic dairy farming and integrated biogas and bioethanol production. Dalgaard T1, Pugesgaard S1, Jørgensen U1, Olesen JE1, Møller HB1 and Jensen ES2 1) Dept. Agroecology and Environment. Faculty of Agricultural Sciences (DJF), University of Aarhus. DK-8830 Tjele. Denmark. Contact: [email protected] 2) Biosystems Department, Risø DTU, The National Laboratory for Sustainable Energy, The Technical University of Denmark DK-4000 Roskilde, Denmark The vision of organic farming systems, independent of fossil energy resources, with significantly lower nutrient losses, and no net contribution to the greenhouse gas emissions might be fulfilled via the integration of biogas production. This is an important hypothesis investigated in the www.bioconcens.elr.dk/uk/ research project. This poster illustrates preliminary results from a model for the fossil energy balance, Nitrogen losses, and greenhouse gas emissions in a 1000 ha energy catchment with organic dairy farming and integrated biogas production in Denmark. The model will draw on results from previous models (e.g the farmGHG model), and includes a number of organic dairy farm type components, including information on livestock production, housing, manure storage, manure and fodder import/export, crop rotations, yield levels, and soil types. In addition, a biogas plant model component evaluates effects of the inclusion of variable amounts of manures and crop residues from the specified farm types, into the biogas energy production. The model is intended to result in an overall catchment balance for the following three types of indicators: 1) the fossil energy use – i.e. the net fossil energy use minus the bioenergy production, 2) losses of Nitrogen in the form of nitrates, ammonia and nitrous oxide, and 3) the emission of the three main greenhouse gasses from agriculture: carbon dioxide, nitrous oxide and methane, measured in carbon dioxide equivalents. Moreover, these indicator values are specified for each of the farm types included in the model, and for the biogas plant component. Finally, selected model results are discussed in relation to the overall hypothesis of the research project, and it is discussed how the integration of biogas production in organic farming, can help to improve the self-sufficiency in Nitrogen, and thereby reduce the import of nutrients to the organic farming systems

    Hvordan kan økologisk jordbrug være med til at styrke vækst og udvikling i landdistrikterne?

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    Øget økologisk jordbrug kan, hvis omlægningen designes rigtigt, bidrage til udviklingen i landdistrikterne. Dette belyses med en række eksempler. En kortlægning af økologisk jordbrugs udbredelse i Danmark viser, at de områder, hvor der i dag er meget økologisk jordbrug, i vid udstrækning er sammenfaldende med de områder, hvor der er et særligt behov for udvikling i landdistrikterne. Det er således et vigtigt at belyse, hvorledes den økologiske jordbrugsproduktion bedst tilrettelægges, så den bidrager til landdistriktsudviklingen i disse områder

    Survey of Danish food industry firms' view on policies that impact the food industry

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    Identification of a novel type of spacer element required for imprinting in fission yeast

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    Asymmetrical segregation of differentiated sister chromatids is thought to be important for cellular differentiation in higher eukaryotes. Similarly, in fission yeast, cellular differentiation involves the asymmetrical segregation of a chromosomal imprint. This imprint has been shown to consist of two ribonucleotides that are incorporated into the DNA during laggingstrand synthesis in response to a replication pause, but the underlying mechanism remains unknown. Here we present key novel discoveries important for unravelling this process. Our data show that cis-acting sequences within the mat1 cassette mediate pausing of replication forks at the proximity of the imprinting site, and the results suggest that this pause dictates specific priming at the position of imprinting in a sequence-independent manner. Also, we identify a novel type of cis-acting spacer region important for the imprinting process that affects where subsequent primers are put down after the replication fork is released from the pause. Thus, our data suggest that the imprint is formed by ligation of a not-fullyprocessed Okazaki fragment to the subsequent fragment. The presented work addresses how differentiated sister chromatids are established during DNA replication through the involvement of replication barriers

    Potentialet for omlægning til økologisk jordbrug i Danmark

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    Potentialet for omlægning til økologisk jordbrug i Danmark
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