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| Registros recuperados: 129 | |
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| Melander, Bo; Rasmussen, Ilse A.; Olesen, Jørgen E.. |
| Fertility building measures are important components in improving the productivity of organic cropping systems without livestock. However, some measures seem to be incompatible with the control of perennial weeds that can have adverse effects such as significant weed competition. The influence of fertility building measures (N2-fixing crops in the crop sequence, cover crops and manuring) and the abundance of perennial weeds were studied in a long-term crop rotation experiment at two locations in Denmark. The aim was to gain insight into the factors that influence the growth of perennial weed species occurring in mixed stands. Data were obtained from three cycles of four-year arable crop rotations comprising various cash crops in rotations with and... |
| Tipo: Journal paper |
Palavras-chave: Weed management. |
| Ano: 2016 |
URL: http://orgprints.org/29791/1/Published_paper.pdf |
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| Olesen, Jørgen E.; Askegaard, Margrethe. |
| The crop rotation is a crucial and integral part of organic farming systems. It must be designed to maintain and exploit soil fertility, and to minimise the impacts on environment, e.g. through nitrate leaching. Crop rotations in organic farming typically include legume crops to provide nitrogen fixation and improve soil fertility. Catch crops are also commonly used, if demands for soil tillage to control perennial weeds allow. This paper presents results on nitrate leaching from a field experiment with comparison of three different crop rotations with and without catch crops designed for organic farming. |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Farming Systems. |
| Ano: 2003 |
URL: http://orgprints.org/3857/1/3857.pdf |
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| Askegaard, Margrethe; Olesen, Jørgen E.; Rasmussen, Ilse A.. |
| A crop rotation experiment was established in 1996/97 at three locations representing different soil types and climates. Three factors were tested: i) crop rotation with different proportions of N2-fixing crops, ii) with and without a catch crop, and iii) with and without animal manure. A green manure crop increased yields in the following cereal crops, but at the rotational level, total yields were larger in crop rotations without a green manure crop. There were positive effects of animal manure and catch crops on yield. However, except for the coarse sandy soil, the yield effects of catch crops and animal manure decreased over time when a grass-clover green manure was included in the rotation. It appeared that the buffering effect of clover can... |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Crop combinations and interactions; Specific methods. |
| Ano: 2005 |
URL: http://orgprints.org/4805/4/Askegaard_etal_4p_revised%2Ded.doc |
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| Rasmussen, Ilse A.; Askegaard, Margrethe; Olesen, Jørgen E.. |
| The plant protection carried out in the Danish crop rotation experiment is described. These measures can be quite different in the different systems. While mechanical weed control can be carried out in systems without catch crops, it is not possible to do so in systems with catch crops without affecting the establishment of the catch crop. The occurrence of weeds, pests and diseases is recorded, and the results are described. Since the results are only from the two first years of the experiments, it is not possible to conclude anything about the crop rotations as such. There are however differences related to the other experimental treatments in the experiment: the presence or absence of catch crops and manure. Only in very few cases are the differences... |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Weed management Crop health; Quality; Protection Cereals; Pulses and oilseeds. |
| Ano: 1999 |
URL: http://orgprints.org/247/1/DARCOF1.PDF |
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| Zhao, Jin; De Notaris, Chiara; Olesen, Jørgen E.. |
| Nitrate leaching losses from arable cropping systems cause severe damages to the environmental services worldwide. There is a considerable need for methods that allow rapid, easy and area covering detection of nitrate leaching to guide N management. We used three years of data from the 5th cycle of a long-term crop rotation experiment in Denmark to quantify the relationships between nitrate leaching in autumn and winter and field conditions in autumn as defined by three vegetation indices [VIs; Ratio Vegetation Index (RVI), Normalized Difference Vegetation Index (NDVI), Ratio Red Edge (RRE)] in autumn. Following cereal crops, catch crops significantly reduced nitrate leaching in autumn and winter, whereas this was only the case for one out of the three... |
| Tipo: Journal paper |
Palavras-chave: Nutrient turnover; Air and water emissions; Farm nutrient management. |
| Ano: 2019 |
URL: http://orgprints.org/35137/1/Manuscript-20190324.pdf |
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| Djurhuus, Jørgen; Olesen, Jørgen E.. |
| A field experiment is conducted which focuses on different aspects of crop rotations for cereal production in organic farming. Three factors are included in the experiment in a factorial design: A) fraction of grass-clover and pulses in the rotation (crop rotation), B) catch crop (with or without catch crop or bi-cropped clover), and C) manure (with or without animal manure applied as slurry). The experiment is conducted at four locations (Jyndevad, Foulum, Flakkebjerg and Holeby), representing different soil types and climate regions in Denmark. There are 64 experimental plots at both Jyndevad and Foulum, 72 at Flakkebjerg and 12 at Holeby. In autumn 1996 soil samples were taken for soil chemical and physical characterisation. The soil horizons were... |
| Tipo: Report |
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| Ano: 2000 |
URL: http://orgprints.org/1814/1/D0033.doc |
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| Olesen, Jørgen E.; Hansen, Elly M.; Askegaard, Margrethe; Rasmussen, Ilse A.. |
| The effect of nitrogen (N) supply and weeds on grain yield of spring barley was investigated in an organic farming crop rotation experiment on three different soil types in Denmark from 1997 to 2001. Three experimental factors were included in the experiment in a factorial design: 1) crop rotation (lupin or pea/barley as previous crop to barley), 2) cover crop (with and without), and 3) manure (with and without). The crop rotations included grass-clover as a green manure crop. Animal manure was applied as slurry in rates corresponding to 40% of the N demand of the cereal crops. Application of 50 kg NH4-N ha-1 in manure (slurry) increased barley grain DM yield by 1.0 to 1.3 Mg DM ha-1, whereas the use of cover crops (primarily perennial ryegrass)... |
| Tipo: Journal paper |
Palavras-chave: Farming Systems. |
| Ano: 2007 |
URL: http://orgprints.org/3852/2/3852.pdf |
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| Muller, Adrian; Olesen, Jørgen E.; Davis, Joan; Dytrtova, Karolina; Gattinger, Andreas; Lampkin, Nicolas; Niggli, Urs. |
| Climate change mitigation is urgent and adaptation to climate change is crucial, particularly in agriculture, where food security is at stake. Agriculture, currently responsible for 20-30% of global greenhouse gas emissions counting direct and indirect agricultural emissions), can however contribute to both climate change mitigation and adaptation. The main mitigation potential lies in the capacity of agricultural soils to sequester CO2 through building organic matter. This potential can be realized by employing sustainable agricultural practices, such as those commonly found within organic farming systems. Examples of these practices are the use of organic fertilizers and crop rotations including legumes leys and cover crops. Mitigation is also achieved... |
| Tipo: Working paper |
Palavras-chave: "Organics" in general; Air and water emissions. |
| Ano: 2012 |
URL: http://orgprints.org/20174/1/EditorialContribution_OrganicAgricultureAndClimateChange_11_4_2012_FiBLTitle.pdf |
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| Rasmussen, Ilse A.; Askegaard, Margrethe; Olesen, Jørgen E.. |
| Danish experiments with cereal-based organic crop rotations have shown that the short-term results (the first course, up to four years after conversion) are different from those obtained in the longer-term (the second course, fifth to eighth year after conversion). Yield gain from use of manure increased from the first to the second course on a sandy soil, but decreased on loamier soils. Yield gain from leguminous catch crops increased from the first to the second course in a crop rotation without grass-clover. Some of these effects were caused by buffering effects of the grass-clover, other effects were caused by changes in soil fertility over time. |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Crop combinations and interactions. |
| Ano: 2006 |
URL: http://orgprints.org/7680/1/Rasmussen_IA_et_al.doc |
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| Rasmussen, Ilse A.; Askegaard, Margrethe; Olesen, Jørgen E.. |
| In long-term organic crop rotation experiments for cereal production, stubble cultivation to control perennial weeds increased nitrogen leaching compared to catch crops grown after harvest. Stubble cultivation contributed to the control of Elymus repens on a sandy soil, but not to the control of Cirsium arvense on a loamy soil. Manure application had a tendency to decrease E. repens density in one rotation at the sandy soil. Grass-clover green manure decreased C. arvense in the succeeding crops. Despite high infestations of perennial weeds, yields were at the same level with as without stubble cultivation. The results point to an important dilemma in organic farming: should the farmer control perennial weeds in the stubble at the expense of losing nitrogen... |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Specific methods. |
| Ano: 2005 |
URL: http://orgprints.org/4451/4/Rasmussen_etal_4p_revised%2Ded.doc |
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| Olesen, Jørgen E.; Rasmussen, Ilse Ankær; Askegaard, Margrethe. |
| There is an increasing demand for organically grown cereal grains in Denmark, which is expected to cause a change in the typical organic farm structure away from dairy farming and towards arable farming. Such a change may reduce the stability of the farming systems, because of decreasing soil fertility and problems with weed control. There have only been a limited number of studies under temperate conditions in Europe and North America, where different crop rotations have been compared under organic farming or similar production conditions. |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Farming Systems. |
| Ano: 2000 |
URL: http://orgprints.org/360/1/B0050.pdf |
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| De Notaris, Chiara; Rasmussen, Jim; Sørensen, Peter; Melander, Bo; Olesen, Jørgen E.. |
| Legume-based cover crop (CC) mixtures can increase nitrogen (N) availability in arable systems, reducing the need for external N inputs, as they retain soil N and fix atmospheric N2. However, they need sufficient biomass accumulation to influence soil N availability. Early establishment through undersowing can improve CC growth and plant N accumulation, but competition with the main crop should be minimized. This study aimed to investigate the effect of main crop inter-row spacing (12, 18, 24 cm), manure application (without, with) and CC undersowing (early, late, no cover crop) on N accumulation in a legume-based CC mixture and the residual N effect on the following crop. We conducted a field experiment in Denmark with spring wheat as main crop and spring... |
| Tipo: Journal paper |
Palavras-chave: Crop combinations and interactions; Farm nutrient management. |
| Ano: 2019 |
URL: http://orgprints.org/35015/1/De%20Notaris%202019_cover%20crop%26row%20spacing.pdf |
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| De Notaris, Chiara; Sørensen, Peter; Rasmussen, Jim; Olesen, Jørgen E.. |
| Increasing the row space of spring wheat from 12 to 24 cm, but maintaining the same seeding density, didn´t decrease its yield. On the other hand, it positively influenced the growth of the undersown catch crop, a mixture of red clover, white clover, rye grass and chicory. |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Crop combinations and interactions; Nutrient turnover; Weed management; Farm nutrient management. |
| Ano: 2016 |
URL: http://orgprints.org/30876/1/Session%203-57-58.pdf |
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| Olesen, Jørgen E.. |
| Så kom nedbøren. Efter det meget varme og tørre forår er det helt rart med lidt almindeligt køligt regnvejr. På sandjorden på Jyndevad er der allerede vandet tre gange. Det skyldes dog delvist at vi i år har ændret vandingspraksis. I de tidligere år har vi benytte gængs praksis med at vande op til fuld markkapacitet. Nyere forskningsresultater viser dog, at det på sandjord er meget vanskeligt at fugte jorden op igen efter en tør periode. Vandet vil have en tendens til at strømme ned i nogle enkelte "fingre" i jorden. Her kan der samtidigt ske udvaskning af især kvælstof. Vi har derfor i år valgt kun at vande med ca. 15 mm ved et vandunderskud på 30 mm. Erfaringer fra andre forsøg på Jyndevad viser, at det totalt set vil kunne spare vand, uden at det... |
| Tipo: Newspaper or magazine article |
Palavras-chave: Farming Systems. |
| Ano: 1999 |
URL: http://orgprints.org/363/1/E0047.pdf |
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| Olesen, Jørgen E.; Thorup-Kristensen, Kristian. |
| Brugen af efterafgrøder har to hovedformål: reduceret kvælstofudvaskning og øget N-forsyning til efterfølgende afgrøder. Efterafgrødens nyttevirkning i den efterfølgende afgrøde afhænger af, om kvælstoffrigivelsen tidsmæssigt falder sammen med afgrødens behov for kvælstof. Flere forsøg gennemført ved Danmarks JordbrugsForskning tyder på at man kan forbedre eftervirkningen af ef-terafgrøder betydeligt ved at vælge det helt rigtige nedmuldningstidspunkt. Det handler ikke blot om nedmuldning enten efterår eller forår. Forårsnedmuldning må ikke ske for sent. Efterårsned-muldning bør kun bruges på lerjorderne, og det må ikke ske for tidligt. |
| Tipo: Newspaper or magazine article |
Palavras-chave: Crop combinations and interactions. |
| Ano: 2003 |
URL: http://orgprints.org/1811/1/E0068.doc |
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| Registros recuperados: 129 | |
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