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Registros recuperados: 65
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Alternative jordbearbejdningsmetoder Organic Eprints
Rasmussen, Jesper.
Præsentation om alternative jordbearbejdningsmetoder.
Tipo: Conference paper, poster, etc. Palavras-chave: Soil tillage.
Ano: 2000 URL: http://orgprints.org/433/1/jordbearb.pdf
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Alternative versus conventional attitudes in higher agricultural education Organic Eprints
Rasmussen, Jesper; Kaltoft, Pernille.
From radical positions it is argued that it will take paradigmatic transformations to develop a sustainable agriculture and that values and attitudes have to be changed. To find out if teachers and students in higher agricultural education are motivated for radical changes a survey based on the Alternative-Conventional Agriculture Paradigm Scale (ACAP-scale) was conducted. The ACAP-scale shows how people relate to the alternative and conventional agricultural paradigm and it shows their overall understanding of how agriculture works and relates to the physical and social environment. This study showed that the ACAP-scale is a suitable method for quantitative assessment of attitudes to agriculture in a broader context. Among students and faculty members at...
Tipo: Journal paper Palavras-chave: "Organics" in general.
Ano: 2003 URL: http://orgprints.org/641/1/Alternative_vs_conventional_attitudes.pdf
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Are we making progress in mechanical weed control research? Organic Eprints
Rasmussen, Jesper.
This study investigates whether researchers’ perceptions of good research are in agreement with current research practice as reflected in Weed Research. A high degree of agreement is assumed to indicate progress. The instrument used to survey researchers perceptions was a questionnaire consisting of 28 items related to (1) research methodologies, (2) research priorities, (3) quality of publications, (4) future developments in technology and agriculture and (5) general attitudes to alternative and conventional agriculture. Questions about gender and personal research engagement were also laid down in the questionnaire. The questionnaire was sent out by e-mail to about 140 researchers on the mailing list of the EWRS – Physical and Cultural Weed Control...
Tipo: Conference paper, poster, etc. Palavras-chave: Research methodology and philosophy; Weed management.
Ano: 2004 URL: http://orgprints.org/2443/1/Are_we_making_progress.pdf
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Are we making progress in mechanical weed control research? Organic Eprints
Rasmussen, Jesper.
This study investigates whether researchers’ perceptions of good research are in agreement with current research practice as reflected in Weed Research. A high degree of agreement is assumed to indicate progress. The instrument used to survey researchers perceptions was a questionnaire consisting of 28 items related to (1) research methodologies, (2) research priorities, (3) quality of publications, (4) future developments in technology and agriculture and (5) general attitudes to alternative and conventional agriculture. Questions about gender and personal research engagement were also laid down in the questionnaire. The questionnaire was sent out by e-mail to about 140 researchers on the mailing list of the EWRS – Physical and Cultural Weed Control...
Tipo: Conference paper, poster, etc. Palavras-chave: Research methodology and philosophy; Weed management.
Ano: 2004 URL: http://orgprints.org/2500/1/EWRS_JR.pdf
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Assessment of leaf cover and crop soil cover in weed harrowing research using digital images Organic Eprints
Rasmussen, Jesper; Nørremark, Michael; Bibby, Bo Martin.
Objective assessment of crop soil cover, defined as the percentage of leaf cover that has been buried in soil due to weed harrowing, is crucial to further progress in post-emergence weed harrowing research. Up to now, crop soil cover has been assessed by visual scores, which are biased and context dependent. The aim of this study was to investigate whether digital image analysis is a feasible method to estimate crop soil cover in the early growth stages of cereals. Two main questions were examined: (1) how to capture suitable digital images under field conditions with a standard high-resolution digital camera and (2) how to analyse the images with an automated digital image analysis procedure. The importance of light conditions, camera angle, size of...
Tipo: Journal paper Palavras-chave: Weed management.
Ano: 2007 URL: http://orgprints.org/11007/1/11007.pdf
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Automated intelligent rotor tine cultivation and punch planting to improve the selectivity of mechanical intra-row weed control Organic Eprints
Rasmussen, Jesper; Griepentrog, Hans W.; Nielsen, J.; Henriksen, Christian Bugge.
There is much emphasis on technical aspects related to sensor or mapping techniques, which enable so-called intelligent cultivators to target the intra-row spaces within crop rows. This study investigates (i) an expected advantage of an intelligent rotor tine cultivator (the cycloid hoe) in terms of crop-weed selectivity and (ii) an expected synergistic effect between punch planting and post-emergence weed harrowing in terms of improved crop-weed selectivity. Selectivity is defined as the relationship between weed control and associated crop density decline one week after cultivation, and punch planting is a sowing technique where holes are created in the ground with a minimum of soil disturbance and seeds are inserted into them, without soil disturbance...
Tipo: Journal paper Palavras-chave: Weed management.
Ano: 2012 URL: http://orgprints.org/21136/8/21136.pdf
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Automated intelligent rotor tine cultivation and punch planting to improve the selectivity of mechanical intra-row weed control Organic Eprints
Rasmussen, Jesper; Griepentrog, Hans W.; Nielsen, J.; Henriksen, Christian Bugge.
There is much emphasis on technical aspects related to sensor or mapping techniques, which enable so-called intelligent cultivators to target the intra-row spaces within crop rows. This study investigates (i) an expected advantage of an intelligent rotor tine cultivator (the cycloid hoe) in terms of crop-weed selectivity and (ii) an expected synergistic effect between punch planting and post-emergence weed harrowing in terms of improved crop-weed selectivity. Selectivity is defined as the relationship between weed control and associated crop density decline one week after cultivation, and punch planting is a sowing technique where holes are created in the ground with a minimum of soil disturbance and seeds are inserted into them, without soil disturbance...
Tipo: Journal paper Palavras-chave: Weed management.
Ano: 2012 URL: http://orgprints.org/20603/2/20603.pdf
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Beskidte rækkeafgrøder giver ukrudt i kornet Organic Eprints
Rasmussen, Ilse A.; Rasmussen, Jesper.
Mislykkes bekæmpelsen af ukrudt i rækkeafgrøder, kan det give store ukrudtsproblemer flere år senere, viser ny resultater fra danske forsøg.
Tipo: Newspaper or magazine article Palavras-chave: Production systems; Weed management.
Ano: 2000 URL: http://orgprints.org/261/1/Renmajs_1.jpg
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Bias in peer review of organic farming grant applications Organic Eprints
Rasmussen, Jesper; Langer, Vibeke; Alrøe, Hugo Fjelsted.
An analysis of peer reviews of 84 organic farming grant applications, submitted to The Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning (FORMAS) in 2001 was carried out to investigate whether peer reviews were influenced by the peer reviewers’ affiliation to organic agriculture research and to what degree peer reviewers distinguish between scientific quality and societal relevance. Fifteen reviewers were grouped in three groups (1) scientists with affiliation to organic farming research, (2) scientists without affiliation to organic farming research and (3) users of the research. The scientist groups assessed societal relevance of the grant applications and scientific quality as a sum of three scientific criteria and the...
Tipo: Journal paper Palavras-chave: Research methodology and philosophy; Research communication and quality.
Ano: 2006 URL: http://orgprints.org/3087/1/Bias_in_peer_review.pdf
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De nye konsulenter og deres holdninger til økologisk jordbrug Organic Eprints
Rasmussen, Jesper; Kaltoft, Pernille.
Holdninger er vigtige, selvbekræftende og konservative Nogle holdninger er overfladiske, mens andre er dybe, da de er kædet sammen med basale værdier hos det enkelte menneske. Det er de dybere holdninger, vi beskæftiger os med i det følgende. Denne type holdninger har betydning for hvordan vi oplever og forstår verden, og hvordan vi handler. Holdningerne og værdierne hjælper os med at finde sammenhæng og mening i tilværelsen, og de får os til at føle harmoni mellem det vi opfatter som rigtigt, og det vi gør. Holdninger er selvbekræftende, fordi vi har behov for at opleve sammenhæng mellem oplevelse, forståelse og handling. De dybe holdninger er konservative, fordi vi ikke kan ændre dem fra den ene dag til den anden. Dette er godt, fordi vi ville komme...
Tipo: Conference paper, poster, etc. Palavras-chave: Surveys and statistics.
Ano: 2002 URL: http://orgprints.org/450/1/Holdninger%2Dkons.pdf
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Digital image analysis offers new possibilities in weed harrowing research Organic Eprints
Rasmussen, Jesper; Nørremark, Michael.
Two field experiments were carried out in winter wheat to determine the optimal intensity and timing of weed harrowing. Each experiment was designed to create a series of intensities by increasing the number of passes at varying growth stages. Visual assessments and digital image processing were used to assess crop soil cover associated with weed harrowing. The study showed that winter wheat responded differently to weed harrowing at different growth stages. In autumn, the crop was severely damaged due to high degrees of crop soil cover and poor recovery resulting in crop yield losses in the range of 7 % to 22 %. In early spring, the crop showed some variability in the ability to recover from soil cover. The best results in spring were obtained at growth...
Tipo: Journal paper Palavras-chave: Weed management.
Ano: 2006 URL: http://orgprints.org/10474/1/10474.pdf
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Digital images for assessing soil cover of crop plants Organic Eprints
Rasmussen, Jesper; Nørremark, Michael.
The main drawback by using crop soil cover in weed harrowing research is that it is assessed by visual scores, which are biased and context dependent. This problem may be solved by using digital image analysis. In this paper a new image capture standard and digital image analysis procedure was used to illustrate three key issues in relation to weed harrowing; selectivity, resistance and recovery. All issues require reliable assessments of crop soil cover. Crop soil cover was deduced from assessments of leaf cover, which is defined as the proportion of pixels in digital images determined to be green. Objective assessments of leaf cover and crop soil cover showed that the selectivity of weed harrowing in winter wheat and spring barley was unaffected by...
Tipo: Conference paper, poster, etc. Palavras-chave: Weed management.
Ano: 2007 URL: http://orgprints.org/10759/1/10759.pdf
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Digital images for assessing soil cover of crop plants Organic Eprints
Rasmussen, Jesper; Nørremark, Michael.
The main drawback by using crop soil cover in weed harrowing research is that it is assessed by visual scores, which are biased and context dependent. This problem may be solved by using digital image analysis. In this paper a new image capture standard and digital image analysis procedure was used to illustrate three key issues in relation to weed harrowing; selectivity, resistance and recovery. All issues require reliable assessments of crop soil cover. Crop soil cover was deduced from assessments of leaf cover, which is defined as the proportion of pixels in digital images determined to be green. Objective assessments of leaf cover and crop soil cover showed that the selectivity of weed harrowing in winter wheat and spring barley was unaffected by...
Tipo: Conference paper, poster, etc. Palavras-chave: Weed management.
Ano: 2007 URL: http://orgprints.org/10758/1/10758.pdf
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Effect of deep-rooted plant species on 15Nitrogen uptake and herbage yield in temporary agricultural grasslands Organic Eprints
Pirhofer-Walzl, K.; Eriksen, Jørgen; Rasmussen , Jim; Soegaard, Karen; Høgh-Jensen, Henning; Rasmussen, Jesper.
Aim is to ncrease of plant diversity has been suggested to enhance grassland productivity and resource use efficiency. Most studies on agricultural grasslands have focused on functional diversity of mixtures comprising legumes and non-legumes, but there is little knowledge of plant nutrient acquisition from deep- and shallow-rooted grassland plant species. To investigate whether deep-rooted (chicory: Cichorium intybus L.; Lucerne: Medicago sativa L.) and shallow-rooted (perennial ryegrass: Lolium perenne L.; white clover: Trifolium repens L.) grassland plant species differ in herbage yield and depth dependent soil N-access, we investigated in the field if 1) a mixture comprising shallow- and deep-rooted grassland plant species has greater herbage yields...
Tipo: Journal paper Palavras-chave: Crop combinations and interactions.
Ano: 2012 URL: http://orgprints.org/20647/4/20647.pdf
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Effect of four plant species on soil 15N-access and herbage yield in temporary agricultural grasslands Organic Eprints
Pirhofer-Walzl, Karin; Eriksen, Jørgen; Rasmussen , Jim; Høgh-Jensen, Henning; Søegaard, Karin; Rasmussen, Jesper.
Positive plant diversity-productivity relationships have been reported for experimental semi-natural grasslands (Cardinale et al. 2006; Hector et al. 1999; Tilman et al. 1996) as well as temporary agricultural grasslands (Frankow-Lindberg et al. 2009; Kirwan et al. 2007; Nyfeler et al. 2009; Picasso et al. 2008). Generally, these relationships are explained, on the one hand, by niche differentiation and facilitation (Hector et al. 2002; Tilman et al. 2002) and, on the other hand, by greater probability of including a highly productive plant species in high diversity plots (Huston 1997). Both explanations accept that diversity is significant because species differ in characteristics, such as root architecture, nutrient acquisition and water use efficiency,...
Tipo: Journal paper Palavras-chave: Crop husbandry; Biodiversity and ecosystem services; Environmental aspects.
Ano: 2013 URL: http://orgprints.org/23296/1/PLANT%20AND%20sOIL.pdf
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Ensidige holdninger i undervisningen - hvad stiller vi op med dem? Organic Eprints
Rasmussen, Jesper; Kaltoft, Pernille.
Holdninger og værdier må nødvendigvis spille en rolle i Landbohøjskolens uddannelser, da uddannelserne retter sig mod professioner, som udøves i et værdipluralistisk samfund. Vi kan derfor ikke lade som om, værdier og holdninger enten ikke eksisterer eller er ens for alle. Dette udfordrer den grundholdning, som præger Landbohøjskolen, hvor såkaldt objektiv faglighed er i højsædet.
Tipo: Newspaper or magazine article Palavras-chave: Research methodology and philosophy.
Ano: 2002 URL: http://orgprints.org/435/1/Hold_%2D_ensidig.pdf
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Erfaringer med nye teknologier i rækkeafgrøder Organic Eprints
Rasmussen, Jesper.
Ukrudt inde i rækkerne i udplantede grønsagskulturer kan nu bekæmpe med automatiserede mekaniske rensere. I udsåede kulturer er det vanskeligere.
Tipo: Conference paper, poster, etc. Palavras-chave: Weed management.
Ano: 2011 URL: http://orgprints.org/18219/1/18219a.pdf
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Falsk såbed sparer tid til roehakning Organic Eprints
Rasmussen, Jesper.
Etablerer man et falsk såbed i roemarken, kan man glæde sig over mindre ukrudt, men samtidig falder udbyttet. I artiklen præsenteres en model, som kan anvendes til at beregne hvor meget tid der kan spares til håndhakning ved at udsætte såtidspunktet og hvor meget udbytte der tabes.
Tipo: Newspaper or magazine article Palavras-chave: Root crops; Weed management; Soil tillage.
Ano: 2004 URL: http://orgprints.org/2530/1/Falsk.pdf
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Forage herbs improve mineral composition of grassland herbage Organic Eprints
Pirhofer-Walzl , K.; Søegaard, Karen; Høgh-Jensen, Henning; Eriksen, Jørgen; Sanderson, M.A.; Rasmussen , Jim; Rasmussen, Jesper.
Provision of an adequate mineral supply in the diets of ruminants fed mainly on grassland herbage can present a challenge if mineral concentrations are suboptimal for animal nutrition. Forage herbs may be included in grassland seed mixtures to improve herbage mineral content, although there is limited information about mineral concentrations in forage herbs. To determine whether herbs have greater macro- and micromineral concentrations than forage legumes and grasses, we conducted a 2-year experiment on a loamy-sand site in Denmark sown with a multi-species mixture comprised of three functional groups (grasses, legumes and herbs). Herb species included chicory (Cichorium intybus L.), plantain (Plantago lanceolata L.), caraway (Carum carvi L.) and salad...
Tipo: Journal paper Palavras-chave: Crop combinations and interactions.
Ano: 2011 URL: http://orgprints.org/19333/1/19333.pdf
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Forskning i ukrudtsharvning får nyt liv med digital billedbehandling Organic Eprints
Rasmussen, Jesper; Nørremark, Michael.
Digital billedbehandling udfylder et metodemæssigt tomrum i forhold til ukrudtsharvning. Med udvikling af en ny billedbehandlingsprocedure er det ikke længere nødvendigt at anvende visuelle bedømmelser af afgrødetildækningen ved ukrudtsharvning. Artiklen giver eksempler på hvordan digital billedbehandling kan anvnedes.
Tipo: Journal paper Palavras-chave: Weed management.
Ano: 2007 URL: http://orgprints.org/10694/1/10694.pdf
Registros recuperados: 65
Primeira ... 1234 ... Última
 

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