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| Registros recuperados: 36 | |
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| 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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| Nielsen, Bea; Thamsborg, Stig Milan; Hansen, Hanne; Ranvig, Hans; Høgh-Jensen, Henning. |
| Two trials were conducted to examine the effect of chicory included in or as additional plots of the ryegrass–white clover pastures on growth, naturally acquired nematode infections and selectivity of chicory by lambs. In Experiment 1, 31 weaned Texel lambs (36±7 kg) grazed either ryegrass–white clover (CTRL) or ryegrass–white clover–hicory pastures (CHIC). In Experiment 2, 30 weaned Shropshire lambs (32±7 kg) grazed either ryegrass–white clover (CTRL) or ryegrass–white clover with access to small additional chicory plots, which corresponded to 3% (CHIC-LO) or 6% of the total grazing area (CHIC-HI). No consistent differences in live weight gain and nematode faecal egg counts were observed in lambs grazing the different pasture types. Sward height on the... |
| Tipo: Journal paper |
Palavras-chave: Feeding and growth. |
| Ano: 2009 |
URL: http://orgprints.org/18302/1/Nielsen_2009_Livestock-Science.pdf |
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| Adu-Gyamfi, J. J.; Myaka, F.A.; Sakala, W.D.; Odgaard, R.; Vesterager, J. M.; Høgh-Jensen, Henning. |
| Maize (Zea mays L.) is a major staple food in Sub-Saharan Africa but low soil fertility, limited resources and droughts keep yields low. Cultivation of maize intercropped with pigeonpea (Cajanus cajan L. Millsp.) is common in some areas of eastern and southern Africa. The objectives of this study were (1) to investigate dry matter, nitrogen (N) and phosphorus (P) accumulation in different plant components of maize-pigeonpea intercropping systems and (2) to report the effects of the intercrops on soil fertility. Maize-pigeonpea intercrops were compared to sole maize grown using farmers’ practices. Intercropping maize and pigeonpea increased (P<0.05) total system yield compared to sole maize in terms of biomass, N and P accumulation. Pigeonpea planted in... |
| Tipo: Journal paper |
Palavras-chave: Farming Systems. |
| Ano: 2007 |
URL: http://orgprints.org/18306/1/18306.pdf |
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| Liu, Yuexian; Langer, Vibeke; Høgh-Jensen, Henning; Egelyng, Henrik. |
| The objective of this study was to evaluate the differences in the energy consumption between the production of certified organic pear, green food certified pear, and conventional pear in two areas in China. Data were collected from interviews with farmers during 2007 and 2008. Energy inputs were significantly higher in organic systems compared with conventional and green systems. Fertilizer was the most important contributor to energy consumption in all three farming systems. Three calculation methods for energy value of manure have been found in the literature: substitution method, by-product method, and thermal method. The choise of various calculation methods for estimating the energy value of manure turns out to have great influence on the results in... |
| Tipo: Journal paper |
Palavras-chave: Environmental aspects. |
| Ano: 2010 |
URL: http://orgprints.org/18297/1/18297.pdf |
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| Pirhofer-Walzl, K.; Rasmussen , Jim; Høgh-Jensen, Henning; Eriksen, Jørgen; Soegaard, Karen; Rasmussen, Jesper. |
| Legumes play a crucial role in nitrogen supply to grass-legume mixtures for ruminant fodder. To quantify N transfer from legumes to neighbouring plants in multi-species grasslands we established a grass-legume-herb mixture on a loamy-sandy site in Denmark. White clover (Trifolium repens L.), red clover (Trifolium pratense L.) and lucerne (Medicago sativa L.) were leaflabelled with 15N enriched urea during one growing season. N transfer to grasses (Lolium perenne L. and xfestulolium), white clover, red clover, lucerne, birdsfoot trefoil (Lotus corniculatus L.), chicory (Cichorium intybus L.), plantain (Plantago lanceolata L.), salad burnet (Sanguisorba minor L.) and caraway (Carum carvi L.) was measured. Neighbouring plants contained greater amounts of N... |
| Tipo: Journal paper |
Palavras-chave: Crop combinations and interactions. |
| Ano: 2012 |
URL: http://orgprints.org/20645/4/20645.pdf |
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| El-Nagger, Ahmed; Ounmaa, Andres; Muukka, Eija; Zaleckas, Ernestas; Abraityté, Gerda; Jansons, Imants; Rasmussen, Jim; Ahnström, Johan; Pirhofer-Walzl, Karin; Jensen, Katherine O’Doherty; Jørgensen, Kirstine F.; Sarunaite, Lina; Bleidere, Mara; Knudsen, Marie Trydeman; Pugliese, Massimo; Nielsen, Merete Højrup Møller; Mugurerza, Natalia Bellostas; Bakewell-Stone, Petra; Hansen, Preben Klarskov; Al-Kufaishi, Sermed Adil Abed-Ali; Kobayashi, Sofie; Rydberg, Torbjörn; Klubova, Vera; Liorancas, Viktoras; Høgh-Jensen, Henning. |
| During one intensive week in October 2005, the authors were gathered to discuss the impact that globalisation has on the Organic Food Systems and the opportunities that globalisation opens up for developing these systems. The meeting took place as a Ph.D. course under the auspices of the Research School of Organic Farming and Food Systems (SOAR; www.soar.dk). All participants research within Organic Agriculture and Food Production in one way or another. |
| Tipo: Journal paper |
Palavras-chave: Food security; Food quality and human health "Organics" in general Food systems Markets and trade Values; Standards and certification. |
| Ano: 2006 |
URL: http://orgprints.org/9333/1/9333.pdf |
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| Oelofse, Myles; Høgh-Jensen, Henning; Abreu, Lucimar Santiago de; Almeida, Gustavo Fonseca de; El-Araby, Ahmed; Hui, Qiao Yu; Sultan, Tursinbek; de Neergaard, Andreas. |
| Certified organic agriculture stipulates a range of principles and standards, which govern farmer practices. The recent global expansion of organic agriculture has raised new challenges for organic agriculture, particularly whether management practices in organic farms are subject to the forces of conventionalisation. We studied changes in agroecological practices in certified organic farms in China,Brazil and Egypt. The study takes departure in the conventionalisation hypothesis and the analysis is framed using organic and agroecological principles. The study focuses on agroecological design principles, inherent to organic agriculture, of diversity in crop production, pest, disease and weed management, and soil fertility management. The research design... |
| Tipo: Journal paper |
Palavras-chave: "Organics" in general; Systems research and participatory research; Food systems; Policy environments and social economy; Research methodology and philosophy; Knowledge management. |
| Ano: 2011 |
URL: http://orgprints.org/23292/7/23292.pdf |
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| Høgh-Jensen, Henning; Kamalongo, D.; Myaka, F.A.; Adu-Gyamfi, J.J.. |
| Maize is a major food crop in eastern and southern Africa and is often cultivated with insufficient supplies of nutrients. The current studies are aimed at diagnosing any potential nutrient limitation in maize under farmers’ conditions using the nutrient content in ear leaf tissue at tasseling stage. The majority of the maize crops were considered below the critical nitrogen (N) content in the ear leaves with mean N content of 1.84%. Phosphorus (P), B and Cu content appeared critically low at three of the four sites. Unique fingerprinting by multivariate statistics was possible for each site when using the proportion of nutrients in the leaf tissue. The content of six macro elements (N, P, K, S, Mg, Ca) at the tasseling stage were found to be able to... |
| Tipo: Journal paper |
Palavras-chave: "Organics" in general; Crop husbandry. |
| Ano: 2009 |
URL: http://orgprints.org/18303/1/18303.pdf |
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| Eriksen, Jørgen; Høgh-Jensen, Henning. |
| Biological N2 fixation in clover is an important source of N in low external-N input farming systems. Using the natural 15N-abundance method, variations in N2 fixation were investigated in grazed and mowed plots of a ryegrass/white clover field. Ryegrass 15N varied considerably, from 0.2 to 5.6‰ under mowed conditions and from -3.3 to 11.6‰ under grazed conditions. Variations in 15N in white clover were lower than in ryegrass, especially in the mowed plots (SE = 0.05‰, n = 20). The variations in the percentage of nitrogen derived from the atmosphere (%Ndfa) in white clover were highest in the grazed plots where it ranged from 12 to 96% (mean = 64%) compared with the mowed plots where it ranged from 64 to 92% (mean = 79%). Thus, the N2 fixation per unit... |
| Tipo: Journal paper |
Palavras-chave: Nutrient turnover. |
| Ano: 1998 |
URL: http://orgprints.org/139/1/PLSO7762.doc |
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| Høgh-Jensen, Henning; Loges, Ralf; Jensen, Erik Steen; Jørgensen, Finn V.; Vinther, Finn P.. |
| Symbiotically fixed N2 (SNF) is an important input of nitrogen (N) in many cropping systems. In spite of this fact, the input of fixed N to a particular cropping system is usually not known, and an exact estimation of the amount of N2 fixed requires laborious measurements. Consequently, there is a demand for a simple and reliable tool to estimate N2 fixation in leguminous crops. A model is here proposed for quantification of SNF in leguminous crops in different arable systems. The model estimates SNF using dry matter yield as input and cropping system specific values for the parameters: N concentration in dry matter and the proportion of the N in the legume that is derived from the atmosphere. Further, the model includes fixed N not included in the... |
| Tipo: Journal paper |
Palavras-chave: Production systems. |
| Ano: 2003 |
URL: http://orgprints.org/316/1/Emperical_N2%2Dfixation_eng_v6.doc |
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| Rasmussen, Jim; Høgh-Jensen, Henning. |
| The C and N dynamics in perennial grass-clover mixtures are not fully understood although such mixtures dominate temperate grassland. The co-existence of clover and grass involves both competition for and transfer of nutrients between the species. The nutrients may originate from leaky root systems, from a rapid turnover of the fine root systems, or from degradation of more stabile organic material. The aim of the study is - to determine the origin of DOC and DON in grass-clover mixtures - to determine the composition of DOC and DON from the species - to investigate the transfer of C and N between grass and clover Method: In a third year grass-clover ley at the KVL research fields, mezotrons were installed to depths of 20, 40 and 60 cm in... |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Nutrient turnover; Specific methods. |
| Ano: 2004 |
URL: http://orgprints.org/3542/1/3542.ppt |
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| El-Naggar, Ahmed; El-Araby, Ahmed; de Neergaard, Andreas; Høgh-Jensen, Henning. |
| A major challenge for low¬-external-input farming systems is to secure the N supply. Lack of synchrony between mineralization of organic N sources and plant N requirements is causing many growers to use different techniques to overcome this problem. One of these techniques is the application of soluble water extracts of different farm residues and plants. A field study was conducted to study the crop uptake of applied 15N-labeled alfalfa and clover extracts as compared to the N uptake from15N-glycine and three levels of 15N-(NH4)2SO4. The results show that total N accumulation in the field crops, squash and lettuce, was primarily affected by the amount of added N (P<0.05) and not by the form in which the N was applied (P>0.05). The utilization... |
| Tipo: Journal paper |
Palavras-chave: Crop husbandry. |
| Ano: 2008 |
URL: http://orgprints.org/18305/1/18305.pdf |
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| Oelofse, Myles; Høgh-Jensen, Henning; Abreu, L.S.; Almeida, Gustavo Fonseca de; Hui, Qiao Yu; Sultan, Tursinbek; de Neergaard, Andreas. |
| Based on three case studies in China and Brazil, this paper explores the terms of access for farmers' participation in certified organic agriculture (OA) and investigates the influence of adoption on productivity, nutrient budgets, income and labour use. Small-scale farmers converting to OA require substantial external production-related, marketing and certification support. Access to OA was strongly dependent upon the type of support available to farmers. Organization based on a contract-farming model resulted in OA only being an option available to a narrow group of farmers, whilst OA initiated by a farmer cooperative provided better access. Gross output was significantly higher for oranges, whilst for the other crops gross output was similar. However,... |
| Tipo: Journal paper |
Palavras-chave: "Organics" in general; Quality and evaluation of inputs. |
| Ano: 2010 |
URL: http://orgprints.org/18301/1/Oelofse_et_al_Ecological_Economics_2010_In_press.pdf |
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| Rasmussen, Jim; Høgh-Jensen, Henning. |
| The C and N dynamics in perennial grass-clover mixtures are not fully understood although such mixtures dominate temperate grassland. The co-existence of clover and grass involves both competition for and transfer of nutrients between the species. The nutrients that are competed for and transferred may originate from leaky root systems, from a rapid turnover of the fine root systems, or from degradation of more stabile organic material. The aim of the present study was to investigate the origin of dissolved organic C and N in perennial grass-clover mixtures. In an existing grass-clover ley, field mezotrons (cylinders with a diameter 30 cm) were installed in the spring of 2003 to depths of 20, 40 and 60 cm. Suction cups was installed beneath the... |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Air and water emissions. |
| Ano: 2005 |
URL: http://orgprints.org/9128/1/9128.pdf |
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| Egelyng, Henrik; Høgh-Jensen, Henning. |
| The first half of this chapter theoretically explores, from a development policy perspective, the nature of institutional environments for certified organic agriculture. The aims are to understand the conditions required, and the prospects, for organic agriculture to thrive, to present a view of global initiatives for research on organic production, and the current degree of institutionalization of organic farming and organic research at the global level. Through institutional analysis of social incentive structures, or game rules, the chapter analyses how certified organics in the North has been operationalized into a single policy instrument through which multiple development benefits are pursued, i.e. institutionalized in a way that enables and... |
| Tipo: Book chapter |
Palavras-chave: Policy environments and social economy; Regulation; History of organics; Knowledge management; Consumer issues; Biodiversity and ecosystem services; Technology assessment. |
| Ano: 2006 |
URL: http://orgprints.org/15401/1/15401.pdf |
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| Høgh-Jensen, Henning. |
| The last meal of an Iron Age man buried in a Danish bog included at least 60 plant species, including barley, linseed and species we now consider weeds. A modern man relies in contrast on a remarkable small number of crop plants, mostly cereal stables like wheat, rice and maize (Evans, 1998). Both land and people in Sub-Saharan Africa are suffering. Natural resource management is in distress and most rural Africans remain poor and food insecure despite widespread macroeconomic, political and sectorial reforms. Most predictions are that these Africans will remain food insecure in the foreseeable future (Pinstrup-Andersen & Pandya-Lorch, 2001). Innovations are, however, changing this landscape much faster than we could expect. A market-oriented... |
| Tipo: Book chapter |
Palavras-chave: Production systems Crop combinations and interactions Food security; Food quality and human health. |
| Ano: 2011 |
URL: http://orgprints.org/23294/7/23294.pdf |
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| Foereid, Bente; Høgh-Jensen, Henning. |
| Decline in carbon content in agricultural soils contributes both to climate change and to soil fertility problems. The CENTURY element dynamics simulation model was tested and adapted for Northern European agricultural conditions using long-term datasets from Askov experimental farm in southern Denmark. The part of the model dealing with decomposition was tested in isolation using a bare fallow experiment and it could predict soil organic matter levels with high accuracy. In the cropping experiments predictions were less accurate. The crop production was not accurately predicted. Predictions were more accurate on loamy than on sandy soils. The model was used to predict the effect of conversion to organic agriculture on carbon sequestration as soil organic... |
| Tipo: Journal paper |
Palavras-chave: Environmental aspects. |
| Ano: 2004 |
URL: http://orgprints.org/18304/1/18304.pdf |
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| Halberg, Niels; Sulser, Timothy B.; Høgh-Jensen, Henning; Rosegrant, Mark W.; Knudsen, Marie Trydeman. |
| The spread of organic and agro-ecological farming (OF) methods in developing countries has raised a debate whether a large scale adoption of OF will increase or decrease global food security. This will however depend on a number of socio-economic factors together with the relative yield levels of OF versus conventional farming systems. Relative yields again depend on a number of agro ecological factors and the characteristics of farming systems before conversion. In areas with intensive high-input agriculture, conversion to OF will most often lead to a reduction in crop yields per ha by 20-45 % in crop rotations integrated with leguminous forage crops. In many areas with low input agricultural systems farmers have little incentive or access to use... |
| Tipo: Book chapter |
Palavras-chave: Food security; Food quality and human health Food systems. |
| Ano: 2006 |
URL: http://orgprints.org/9209/1/9209.pdf |
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| Registros recuperados: 36 | |
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