216 research outputs found
Methodological difficulties of conducting agroecological studies from a statistical perspective
No full textAndré Bianconi, Tommy Dalgaard, Bryan F. J. Manly, José S. Govone, Michael J. Watts, Peter Nkala, Gustavo Habermann, Yanbo Huang, and Adriane B. S. Serapiã
Generating EU-wide endogenous crop yield responses to nitrogen to predict the impact of environmental policies on farm-level cropping systems
No full textEnergi i økologisk jordbrug. Reduktion af fossilt energiforbrug og produktion af vedvarende energi
No full textMålsætningen om at reducere forbruget af fossil energi er klart formuleret i de økologiske principper. Desuden er der både forsyningsmæssige og geopolitiske grunde til, at det kan være klogt at fremtidssikre økologisk jordbrug ved at øge selvforsyningsgraden. Men hidtil er der ikke sket en målrettet indsats inden for økologisk jordbrug på dette felt. Analyser i denne vidensyntese viser dog, at potentialet for produktion af vedvarende energi i økologisk jordbrug er stort, således at det teoretisk set er forholdsvis let at blive selvforsynende med det direkte energiforbrug.
I rapporten er der hovedsageligt fokuseret på energiteknologier, som inden for en kort tidshorisont kan implementeres, og på teknologier, som kan udnyttes decentralt på den enkelte gård eller i lokale fællesanlæg i tråd med nærhedsprincippet. Endvidere er der fokuseret på teknologier, som kan bidrage til at opfylde andre højt prioriterede målsætninger i økologisk jordbrug: Selvforsyning med foder og næringsstoffer samt øget recirkulering
Identification of a novel type of spacer element required for imprinting in fission yeast
No full textAsymmetrical 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
Materials and Methods REFUGIA project working paper
No full textThe organic farming structure has been analysed for all farms in Denmark 2005-2010. In 2005, the average farm size for organic farms was 50 ha, compared to 40 ha for conventional farms. For organic farms the largest average farm size in on sandy soils and for cattle farms, whereas the for conventional farms, the largest farms are on loamy soils, and cash crop, and pig farms.
The farms has been classified into farm types accoring to the EUROSTAT methods. Hobby farms are defined with a number of standard working hours under 1871 timer/år (typically under 10-25 ha). These farms normally are not included in national statistics, but are important to include in the REFUGIA studies, because these farms are important for biodiversity and have a relatively higher number among organic farms. The other farm types are full time farms. If more than 2/3 of the standard gross margin comes from catlle it is a cattle farm, and the same for cash crops. The rest is pig farms and other types of farms (for example poultry and fur animals). Standard rotations are defined for each of these farm types
Økologisk jordbrug beskytter biodiversiteten
No full textØkologisk jordbrug beskytter naturen med sin pesticidfri dyrkning og mindre brug af gødning, men en række andre faktorer er lige så vigtige
LiveM WP4: Methods for regional scale farming systems modelling and uncertainty assessment – sustainability assessment case studies of production, nutrient losses and greenhouse gas emissions from grassland based systems
No full textIn the EU Joint-Programming-Initiative: Modelling European Agriculturewith Climate Change for Food Security (MACSUR, LiveM: http://www.macsur.eu/index.php/livestock-modelling) we develop a research frameworkfor the modelling and sustainability assessment of livestock and grasslandbased farming systems at farm and regional scales.Based on results from related research and model development in Denmark,methodologies used for regional scaling, the description of data requirementsand sources, and methods to predict the effect and effectiveness of climate-and environment related policy measures are developed. In this study we present results from farm modelling in a study areaaround Viborg, Western Denmark using the http://www.Farm-N.dk/ model (Env.Pol. 159 3183-3192), including thedistribution of N-surpluses into different types of losses, and a comparisonwith empirical studies of farm nitrogen balances in the Danish study and fiveadditional European landscapes (Biogeosciences 9, 5303–5321). Based on this,methods and development needs for the mapping and uncertainty assessment ofnutrient losses and greenhouse gas emissions are discussed, referring to the presentdevelopment of the Farm-AC model and ongoing scenario studies in e.g. the www.dNmark.org project. In these scenarios, regional-scale policy measures areimplemented via the responses of a range of stakeholders, such as farmers,public interest groups, regulators and politicians. When modelling the outcomeof the policy measures implementation, it is often assumed that stakeholdersrespond as economically rational entities. However, social and cultural factorsare also known to play a role and modelling methods that permit these factorsto be taken into account will also be discussed
Landscape Agroecology: managing interactions between agriculture, nature and socio-economy
No full textState of the art GIS and database technologies for landscape scale analysis and the modelling of land use and environmental impacts are presented. These methods have been developed at University of Aarhus in multidisciplinary collaboration with other research institutions throughout Europe; for example during the EU research projects www.mea-scope.org and www.sensor-ip.eu. In the years to come, these landscape scale research methods are further developed and integrated with similar frameworks in other EU countries, and used for scenario studies (see for example the landscape components of http://www.nitroeurope.eu/, http://www.darcof.dk/research/darcofiii/refugia.html or http://www.darcof.dk/research/darcofiii/bioconcens.html).
Scenario studies, visualised in geographical information systems, are useful to evaluate possible future landscape developments, and to identify potentials and limitations in combining multiple landscape functions. Here we focus on scenario systems that focus on exploring interactions between landscape functions – e.g. the interactions between farm management, economy, nutrient losses, fauna population dynamics, plant community development etc. Among others, scenarios for drinking water protection via increased set-aside grassland or afforestation are presented. It shows that benefits from subsidies targeted to areas with special interests in protection of drinking waters from nitrogen pollution differ from non-targeted subsidies.
Experience has shown that working with scenarios and involving potential users at an early stage in development are important ways of focussing the work effort and ensuring that relevant tools are developed. Developments in data collection and collation at the EU level will allow similar systems to be developed elsewhere
Models for regional scale farming system evaluation of climate change mitigation options and environmental impact assessment
No full textThe aim of the present paper is to exemplify and discuss the importance of farm scale modeling in relation to The EU Joint Programming Initiative (JPI-FACCE) knowledge hub on Agriculture, Food Security and Climate Change project. In particular, livestock production systems include complex interactions, with non-linear relationships between input factors, production, emissions, local climate as well as natural resources (e.g. soil types, rotational land versus permanent grasslands etc.). Moreover, management options pursued by the different types of farmers and other relevant decision makers are important to integrate. Consequently, results of regional scale impact assessments depend on the farming systems model approach, the approach to upscale results, and the inclusion of the relevant stakeholders and decision makers at the scales considered. Different farming systems models are reviewed, including the existing dynamic and static biophysical models. Finally, procedures for upscaling and validity testing of synthesized model results at regional scales are presented. Based on a discussion of these procedures, recommendations for hot-spot analyses in farming systems with regard to integrated climate change adaptation and mitigation for a sustainable food production are synthesized, and the potentials for integration of recommended policies and farm management options into overarching models in order to assess their impact on the regional to global scales are discussed
Paul A. Wojtkowski, Landscape agroecology, Haworth Press, Inc., New York (2004) ISBN 1-56-022-253-0 330 pp. Price US49.95 (paperback).
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