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| Registros recuperados: 24 | |
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| Kristensen, K.; Willas, J.; Jørgensen, L.N.; Gislum, R.. |
| I forsøg med mange forsøgsled, forsøg på uensartede arealer og forsøg, som af praktiske grunde skal opdeles på mindre enheder, vil det ofte være fordelagtigt at anvende blokke, som ikke indeholder alle forsøgsled. Sådanne ufuldstændige blokke kan konstrueres efter flere forskellige principper. I enfaktorielle forsøg anvendes oftest metoder, som sikrer, at alle par af forsøgsled kan sammenlignes med den samme (og bedst mulige) sikkerhed, mens man i flerfaktorielle forsøg oftest anvender metoder, som sikrer, at de mest interessante effekter (hoved- og/eller vekselvirkninger) kan estimeres bedst muligt. Artiklen viser tre eksempler på anvendelse af ufuldstændige blokforsøg: 1) Sortsforsøg i ærter (enfaktoriel), 2) Frøavlsforsøg med strandsvingel... |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Research methodology and philosophy. |
| Ano: 2003 |
URL: http://orgprints.org/1501/1/KKM_Intern_rapport_nr._184.pdf |
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| Backes, G.; Kristensen, K.; Østergård, H.. |
| In context of a larger project dealing with the traits of barley that are related to organic farming (BAR-OF), we performed an association mapping in order to dertermine the genetic loci linked with the respective traits. In two subsequent years (2002 and 2003), we used field results from 96 barley lines and varieties, partially overlapping between the years. The lines/varieties were grown on three Dansih locations (Flakkebjerg, Foulum and Jyndevad). For Foulum and Flakkebjerg, we observed both fields grown under organic and conventional regime; for Jyndevad only fields cultivated under organic conditions were ecploited. Neither in the organic nor in the conventional fields; diseases were controlled chemically. In the resulting five environments per year,... |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Cereals; Pulses and oilseeds Breeding; Genetics and propagation. |
| Ano: 2007 |
URL: http://orgprints.org/21774/7/21774.pdf |
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| Østergård, H.; Kristensen, K.; Hovmøller, M.S.; Jensen, J.W.. |
| Despite quite intensive testing of varieties, predictions of future performance of varieties, when grown on specific locations, are known to be nearly impossible; this especially within organic growing systems, where no pesticides and fertilizers can help stabilize yield. Therefore, using mixtures of appropriate varieties might be a way to obtain more stable and acceptable yields. Variety mixtures have so far been studied mostly under conventional farming conditions and focus has often been to characterize disease progress of one pathogen. Here we consider simultaneously four important foliar diseases on spring barley grown in organic as well as conventional growing systems. Further, we study the changes in disease severity of variety mixtures when... |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Crop health; Quality; Protection Crop combinations and interactions Breeding; Genetics and propagation Biodiversity and ecosystem services. |
| Ano: 2004 |
URL: http://orgprints.org/8145/1/8145.pdf |
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| Hansen, E.M.; Eriksen, J.; Søegaard, K.; Kristensen, K.. |
| Urinations of ruminants on grazed pastures increase the risk of nitrate leaching. The study investigated the effect of reducing the length of the grazing season on nitrate leaching from a coarse sandy, irrigated soil during 2006-2007. In both years precipitation was above the long-term mean. The experiment was initiated in a 4-year-old grass-clover in south Denmark. Three treatments were included: grazing only (G), spring cut followed by grazing (CG) and both spring and autumn cuts with summer grazing (CGC). Nitrate leaching was calculated by extracting water isolates from 80 cm depth using ceramic suction cups. Because of considerable variation in measured nitrate concentrations, the 32 installed suction cups per treatment were insufficient to reveal... |
| Tipo: Journal paper |
Palavras-chave: Air and water emissions; Farm nutrient management. |
| Ano: 2012 |
URL: http://orgprints.org/20649/7/20649.pdf |
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| Rasmussen, I.A.; Askegaard, M.; Olesen, J.E.; Kristensen, K.. |
| We investigated the effects on annual weeds of location, weed control, manure application and catch crops and their interactions in a crop rotation with cereals and pulses for grain during conversion to organic farming in order to better understand the combined effects of management. An experiment with a four-year crop rotation (spring barley/undersown ley, grass-clover, winter wheat, pea/barley) was carried out from 1997 to 2000 under organic conditions at three locations in Denmark with four treatments: with and without catch crop, and with and without manure. Mechanical weed control was reduced or absent in cereals or pulses with undersown catch crops or grass-clover. Manure application increased weed biomass, but not the proportion of total biomass... |
| Tipo: Journal paper |
Palavras-chave: Cereals; Pulses and oilseeds Crop combinations and interactions Weed management. |
| Ano: 2006 |
URL: http://orgprints.org/7904/1/7904.pdf |
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| Hovmøller, M.S.; Berntsen, J.; Kristensen, K.. |
| Significant increase in severity of powdery mildew,leaf rust and net blotch with increasing N-content in plant leaves 30 days after germination (all years where the relevant diseases were present at a substantial level). This may explain: · Most of the environmental main effects (field) on disease. · Effect of treatments, i.e., treament 4 resulted in reduced N/increased K content in leaves, which coincided with reduced levels of disease. We observed no clear effect of P, Ca, S, and Zn content in leaves on disease. Micronutrients as Cu, Mo and Mn showed significant effects on powdery mildew in one year but not the other; further interpretation may not be possible due to inter-correlation among the effect of micro-nutrients. The diseases had a... |
| Tipo: Working paper |
Palavras-chave: Crop health; Quality; Protection Farm nutrient management. |
| Ano: 2006 |
URL: http://orgprints.org/7914/1/7914.pdf |
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| Eriksen, J.; Askegaard, M.; Kristensen, K.. |
| Four management systems combining high and low livestock densities (0.7 and 1.4 LU ha-1) and different types of organic manure (slurry and straw based FYM) were applied to an organic dairy crop rotation (barley [undersown] – grass-clover – grass-clover – barley/pea – oats – fodder beet) between 1998 and 2001. The effects of the management systems on crop yields and nitrate leaching were measured. In all four years nitrate leaching, as determined using ceramic suction cups, was higher in the three crops following ploughing of grass-clover than under the barley or grass-clover. Overall, no significant differences in nitrate leaching were observed between the management systems. However, the replacement of the winter wheat crop used in the earlier... |
| Tipo: Journal paper |
Palavras-chave: Nutrient turnover. |
| Ano: 2004 |
URL: http://orgprints.org/1824/1/paper.doc |
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| Askegaard, M.; Thomsen, I.K.; Berntsen, J.; Hovmøller, M.S.; Kristensen, K.. |
| In order to obtain a high and stable yield of organic spring barley, production should be optimized according to the specific environment. To test the performance of spring barley varieties under varying cropping conditions, a field experiment was carried out in 2003 and 2004 in a six-field mixed organic crop rotation. We investigated the choice of variety, the order in a rotation,and the application of manure (slurry and farm yard manure; 0 to 120 total-Nha�1) on grain yields of six selected varieties with different characteristics grown in either pure stands or in two spring barley mixtures, each consisting of three varieties. Average grain yield of the barley varieties varied between 3.3 t DM ha-�1 and 4.1 t DM ha-�1. Grain yields of the two... |
| Tipo: Journal paper |
Palavras-chave: Cereals; Pulses and oilseeds. |
| Ano: 2011 |
URL: http://orgprints.org/7853/2/7853.pdf |
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| Melander, B.; Kristensen, J.K.; Kristensen, K.; Mathiassen, S.K.; Nørremark, M.; Kristensen , E.F.. |
| Traditional strategies for controlling Elytrigia repens infestations in organic cropping in Scandinavia are based on repeated post-harvest cultivation. However, post-harvest tillage is undesirable due to the need for retaining nutrients in the cropping systems. There is a need to look for solutions where E. repens can be controlled over a short duration to allow replanting of the soil. A Danish project is investigating new technologies that can meet such requirements. One aspect is to look for methods that physically can destruct the sprouting ability of E. repens rhizome buds. We investigated the effect of heating using hot water and mechanical crushing by pressure on the sprouting ability of exposed rhizome buds. The effect of temperatures < 70oC... |
| Tipo: Journal paper |
Palavras-chave: Weed management. |
| Ano: 2010 |
URL: http://orgprints.org/17901/1/17901.pdf |
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| Melander, B.; Kristensen, J.K.; Kristensen, K.; Mathiassen, S.K.; Nørremark, M.; Kristensen , E.F.. |
| Traditional strategies for controlling Elytrigia repens infestations in organic cropping in Scandinavia are based on repeated post-harvest cultivation. However, post-harvest tillage is undesirable due to the need for retaining nutrients in the cropping systems. There is a need to look for solutions where E. repens can be controlled over a short duration to allow replanting of the soil. A Danish project is investigating new technologies that can meet such requirements. One aspect is to look for methods that physically can destruct the sprouting ability of E. repens rhizome buds. We investigated the effect of heating using hot water and mechanical crushing by pressure on the sprouting ability of exposed rhizome buds. The effect of temperatures <... |
| Tipo: Journal paper |
Palavras-chave: Weed management. |
| Ano: 2011 |
URL: http://orgprints.org/20606/1/20606a.pdf |
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| Eriksen, J.; Hermansen, J.E.; Strudsholm, K.; Kristensen, K.. |
| Nutrient load and distribution on pasture were investigated with fattening pigs that: 1) spend a proportion of or their entire life on pasture, 2) were fed either restrictively or ad libitum, and 3) were weaned at different times of the year. The N and P retention in pigs decreased the longer they were kept on pasture. The contents of soil inorganic N and exchangeable K were significantly raised compared to the soil outside the enclosures but with no differences between treatments. Pig grazing did not affect extractable soil P. Regular moving of huts, feeding and water troughs was effective in ensuring that nutrients were more evenly distributed on the paddocks. Grass cover, as determined by spectral reflectance, was not related to the experimental... |
| Tipo: Journal paper |
Palavras-chave: Nutrient turnover; Pigs; Air and water emissions. |
| Ano: 2006 |
URL: http://orgprints.org/10041/1/10041.pdf |
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| Østergård, H.; Kristensen, K.; Pinnschmidt, H.O.; Hansen, P.K.; Hovmøller, M.S.. |
| Abstract For low-input crop production, well-characterised varieties increase the possibilities of managing diseases and weeds. This analysis aims at developing a framework for analyzing grain yield using external varietal information about disease resistance, weed competitiveness and yield potential and quantifying the impact of susceptibility grouping and straw length scores (as a measure for weed competitiveness) for predicting spring barley grain yield under variable biotic stress levels. The study comprised 52 spring barley varieties and 17 environments, i.e., combinations of location, growing system and year. Individual varieties and their interactions with environments were analysed by factorial regression of grain yield on external variety... |
| Tipo: Journal paper |
Palavras-chave: Crop health; Quality; Protection Weed management Breeding; Genetics and propagation. |
| Ano: 2008 |
URL: http://orgprints.org/14957/1/14957.pdf |
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| Østergård, H.; Kristensen, K.; Jensen, J.W.. |
| Fifty spring barley varieties grown under organic as well as conventional growing conditions in experimental fields in four combinations of year and site were studied. The yield varied much within and between environments (years and sites) and systems. Further, the variation between varieties was substantially and it differed between different environments and systems. Associations between observed grain yield of these varieties and disease and growth characteristics assessed in the official conventional variety testing were compared between the organic and the conventional system. Using factorial regression analysis, the best model for predicting the observed grain yield each year from these characteristics the previous year was found. In this model, the... |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Crop health; Quality; Protection Regulation Breeding; Genetics and propagation. |
| Ano: 2005 |
URL: http://orgprints.org/8149/1/8149.pdf |
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| Østergård, H.; Finckh, M.R.; Fontaine, L.; Goldringer, I.; Hoad, S.P.; Kristensen, K.; Lammerts van Bueren, E.T.; Mascher, F.; Munk, L.; Wolfe, M.S.. |
| A radical shift in our approach to crop production is needed to ensure food security and to address the problems of soil degradation, loss of biodiversity, polluted and restricted water supplies, coupled with a future of fossil fuel limitations and increasingly variable climatic conditions. An interdisciplinary network of European scientists put forward visions for future crop production embracing the complexity of our socio-ecological system by applying the principle of diversity at all levels from soil micro-organisms to plant varieties and cropping systems. This approach, integrated with careful deployment of our finite global resources and implementation of appropriate sustainable technology, appears to be the only way to ensure the scale of system... |
| Tipo: Journal paper |
Palavras-chave: Production systems Soil quality Systems research and participatory research Recycling; Balancing and resource management Breeding; Genetics and propagation Regulation. |
| Ano: 2009 |
URL: http://orgprints.org/21749/1/21749.pdf |
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| Büchse, A.; Krajewski, P.; Kristensen, K.; Pilarczyk, W.. |
| The response from field trials is subject to random variation. This means that two neighbouring plots grown with the same variety and treated in the same way will always yield differently. This also applies to all other recordings made on a continuous scale. The size of the differences will depend on several circumstances such as the variability in the soil, variability in the applied fertilizer, historical events and uncertainty in the recording process. This means that a recorded difference between e.g. two varieties may be due to either a true difference in the response of the two varieties or may be due to random variations. In order to help decide whether the difference is caused by the different varieties or by random variation it is necessary to... |
| Tipo: Book chapter |
Palavras-chave: Surveys and statistics Breeding; Genetics and propagation. |
| Ano: 2007 |
URL: http://orgprints.org/21757/1/21757.pdf |
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| Schjønning, P.; Thomsen, I.K.; Møberg, J.P.; de Jonge, H.; Kristensen, K.; B.T., Christensen. |
| Soil type effects on organic matter turnover are most often ascribed directly to differences in soil clay content. Since soil texture determines the physical characteristics of soil, aggregation and water holding capacity may be more relevant to address in the search for controls of organic matter turnover. Most studies of microbial processes in soils are based on structurally disturbed soil, where the abiotic conditions for the microbial activity may be quite different from those in intact soils. In this study, basic physical characteristics were determined for structurally disturbed and intact soil samples from differently textured soils. Bulk soil was retrieved from 0–20 cm depth at six locations along a textural gradient in an arable field on... |
| Tipo: Journal paper |
Palavras-chave: Nutrient turnover; Soil quality; Soil biology. |
| Ano: 1999 |
URL: http://orgprints.org/726/1/geoderma_99_I.pdf |
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| Registros recuperados: 24 | |
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