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Registros recuperados: 26
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Biodiversity as a tool in crop nutrition Organic Eprints
Thorup-Kristensen, K..
In the abstract it is discussed how increased biodiversity in the choice of crops, catch crops and green manures can be used to improve organic crop rotations. Use of more species with variable characteristics can make it possible to make rotations with reduced losses of nutrients and improve nutrient supply for organically grown crops.
Tipo: Conference paper, poster, etc. Palavras-chave: Air and water emissions; Composting and manuring.
Ano: 2005 URL: http://orgprints.org/7906/1/7906.rtf
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Deep roots of Brassica oleracea have high uptake of 15N-nitrate to 2 meters soil depth Organic Eprints
Kristensen, H.L.; Thorup-Kristensen, K..
• Deep roots may be important for uptake of NO3- by annual crops. A field experiment with the deep rooted crop curly kale (Brassica oleracea L. convar. acephala (DC.) Alef. var. sabellica L.) was performed to investigate root distribution and N uptake in deep soil layers. • Root distribution was investigated by use of minirhizotrons and root extractions to 2.4 m depth. The capacity for crop N uptake was studied by deep 15NO3- placement followed by analysis of plant 15N content after 3-30 days. • The atom percent 15N excess (APE) of plant samples was of similar size after uptake of 15N placed at depths in the range of 0.4-2 m. Root colonisation and start of 15N uptake were synchronized in 2.4 m depth. • The deep roots had higher inflow of 15N compared...
Tipo: Journal paper Palavras-chave: Nutrient turnover; Soil biology; Farm nutrient management; Air and water emissions.
Ano: 2006 URL: http://orgprints.org/7918/1/7918.pdf
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Early decomposer assemblages of soil organisms in litterbags with vetch and rye roots Organic Eprints
Georgieva, S.; Christensen, S.; Petersen, H.; Gjelstrup, P.; Thorup-Kristensen, K..
The assemblages of microbial (bacteria and fungi), microfaunal (protozoa and nematodes) and mesofaunal (microarthropods) populations were studied in decomposing root residues from hairy vetch (Vicia villosa Roth) and rye (Secale cereale L.) in a litterbag field experiment. Litterbags containing vetch or rye root residues were buried in soil at the same day as either vetch or rye winter catch crops were incorporated into the field soil from which the materials were gathered. The litterbags were sampled after 6 weeks in the field. In vetch, bacterial and fungal biomasses were similar whereas fungi dominated microbial biomass in rye. The biomass of the bacterial consuming fauna dominated by nematodes and microarthropods was similar to the biomass of bacteria...
Tipo: Journal paper Palavras-chave: Biodiversity and ecosystem services; Composting and manuring.
Ano: 2005 URL: http://orgprints.org/7900/1/7900.pdf
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Effect of crop management practices on the sustainability and environmental impact of organic and low input food production systems Organic Eprints
Thorup-Kristensen, K..
While organic farming can reduce many of the environmental problems caused by agriculture, organic farming also includes some practices which are questionable in terms of environmental effects. Organic farming practices (rotations, fertilisation regimes, cover crop use) can differ significantly and this leads to large differences in its environmental effects. This leaves considerable scope to improve the environmental effects of organic farming. The environmental aspects of organic farming are discussed, and model simulations are used to illustrate how even moderate changes in organic rotations can have large effects on sustainability, here measured by a simple index of nitrogen lost by leaching relative to nitrogen harvested by the crops. In WP3.3.4 we...
Tipo: Conference paper, poster, etc. Palavras-chave: Biodiversity and ecosystem services.
Ano: 2007 URL: http://orgprints.org/10421/1/thorup%2D2007%2Dcrop_management.pdf
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Effect of deep and shallow root systems on the dynamics of soil inorganic N during 3-year crop rotations Organic Eprints
Thorup-Kristensen, K..
Unused inorganic N (Ninorg) left in agricultural soils will typically leach to deeper soil layers. If it moves below the root zone it will be lost from the system, but the depth of the root zone depends on the crop species grown. In this experiment we studied the effect of three-year crop sequences, with different combinations of deep and shallow rooted crops, on soil Ninorg dynamics to 2.5 m soil depth and the possibility of crop utilization of N leached to deep soil layers. We grew 10 different crop sequences for three years. The crops and catch crops grown were selected to allow different sequences of deep and shallow rooted crops. Very different rooting depths were obtained, from only 0.5 m (leek), to approximately 1.0 m (ryegrass and barley), 1.5 m...
Tipo: Journal paper Palavras-chave: Cereals; Pulses and oilseeds Root crops Vegetables Air and water emissions Composting and manuring.
Ano: 2006 URL: http://orgprints.org/7905/6/7905.pdf
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Effect of green manure management on barley yields and N-recovery Organic Eprints
Hansen, S.; Frøseth, R.B.; Bakken , A.K.; Riley, H.; Thorup-Kristensen, K.; Bleken, M.A..
Mulching of GM herbage can increase cereal yields compared to its removal. However, the same GM herbage removed for biogas production will provide biogas residue that can be used as spring fertilizer to cereals. This will improve N-recovery and reduce the risk for N pollution. Cooperation with existing biogas plants will be more efficient, as building small biogas plants are costly and challenging.
Tipo: Conference paper, poster, etc. Palavras-chave: Cereals; Pulses and oilseeds Composting and manuring Post harvest management and techniques.
Ano: 2013 URL: http://orgprints.org/24600/1/24600.pdf
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Effects of vertical distribution of soil inorganic nitrogen on root growth and subsequent nitrogen uptake by field vegetable crops Organic Eprints
Kristensen, H.L.; Thorup-Kristensen, K..
Information is needed about root growth and N uptake of crops under different soil conditions to increase nitrogen use efficiency in horticultural production. The purpose of this study was to investigate if differences in vertical distribution of soil nitrogen (Ninorg) affected root growth and N uptake of a variety of horticultural crops. Two field experiments were performed each over 2 years with shallow or deep placement of soil Ninorg obtained by management of cover crops. Vegetable crops of leek, potato, Chinese cabbage, beetroot, summer squash and white cabbage reached root depths of 0.5, 0.7, 1.3, 1.9, 1.9 and more than 2.4 m, respectively, at harvest, and showed rates of root depth penetration from 0.2 to 1.5 mm day)1 C)1. Shallow placement of soil...
Tipo: Journal paper Palavras-chave: Nutrient turnover; Farm nutrient management.
Ano: 2007 URL: http://orgprints.org/14749/1/14749.pdf
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Grønne marker Organic Eprints
Hansen, E.M.; Thorup-Kristensen, K.; Jørgensen, J.R..
Grønne marker
Tipo: Report chapter Palavras-chave: Cereals; Pulses and oilseeds.
Ano: 2003 URL: http://orgprints.org/1440/1/Forbedret_kvaellstofudnyttelse.pdf
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High densities of Collembola and mites in organic fields with undersown catch crops Organic Eprints
Axelsen, J.; Thorup-Kristensen, K.; Askegaard, M.; Krogh, P.H..
The abundance and species composition of soil living mites and Collembola were investigated in autumn and winter in field plots with five different types of catch crops and a control plot that was kept free of vegetation. The catch crops, chicory, white clover, garden lupine, and perennial ryegrass were undersown in barley while fodder radish was sown after harvest .The investigation was carried out at a site on sandy loam and a site on coarse sand. At the sandy site densities up to about 250.000 and 100.000 m-2 of mites and Collembola, respectively, were found. At the sandy loam site densities were up to 120.000 mites m-2 and 150.000 Collembola m-2. The densities of both microarthropods were extremely high with up to 120,000 Collembola m-2 and 90,000...
Tipo: Journal paper Palavras-chave: Soil biology; Biodiversity and ecosystem services.
Ano: 2006 URL: http://orgprints.org/7988/1/7988.doc
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Horizontal activites. QLIF subproject 7: Horizontal activities Organic Eprints
Thorup-Kristensen, K.; Lampkin, N.; Elsgaard, L.; van der Burgt, Geert-Jan.
QLIF subproject 7 represents four horizontal activities common to the project, namely: • Environmental and sustainability audits • Cost-benefit analyses and socio-economic impact assessments • Dissemination and technology transfer • Training of graduate and postgraduate researchers Activities in the horizontal research have shown that organic crop production systems generally are more energy-efficient and have lower greenhouse gas emissions than the conventional production. In terms of dissemination the QLIF website has been central and the QLIF newsletter has attracted more than 1000 subscribers. Coupling of the website with the open access database Organic Eprints provides a prospective source of project information that can be accessed also by future...
Tipo: Report Palavras-chave: Policy environments and social economy Environmental aspects Education; Extension and communication.
Ano: 2009 URL: http://orgprints.org/16594/1/16594.pdf
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Kompost af byaffald er velegnet som P-gødning og til jordforbedring Organic Eprints
Thorup-Kristensen, K.; Dresbøll, D.B..
I løbet af få år bliver det formentlig forbudt at bruge konventionel husdyrgødning til økologisk planteproduktion, og derfor er det nødvendigt allerede nu at undersøge alternative gødningskilder. Én mulighed kunne være recirkulering af næringsstoffer gennem kompost af forskellige typer by-affald. Dette er netop blevet undersøgt i projektet RoCo, som er en del af forskningsprogrammet Organic RDD 2.
Tipo: Newspaper or magazine article Palavras-chave: "Organics" in general; Soil.
Ano: 2015 URL: http://orgprints.org/28226/1/28226.pdf
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Mitigation of subsoil recompaction by light traffic and on-land ploughing. II: Root and yield response Organic Eprints
Munkholm, L.J.; Schjønning, P.; Jørgensen, M.H.; Thorup-Kristensen, K..
Plough pans have been shown to severely hamper root development, limit rooting depth and reduce crop yields. We evaluated the effect of plough pan compaction on root and yield response for a winter wheat in a field trial conducted in two neighbouring fields (B3 and B4) on a sandy loam. Plots were mechanically loosened to a depth of 35 cm in 1997 (B3 and B4) and again in 1998 (only B4). Perennial grass/clover was grown with limited traffic intensity in 1998-1999 and 1999-2000 for B3 and B4, respectively. The perennial grass/clover was ploughed under in spring 2000 (B3) and spring 2001 (B4) and oats established. After harvest of oats, winter wheat was established. Recompaction treatments were applied to the mechanically loosened plots in 2000 and 2000+2001...
Tipo: Journal paper Palavras-chave: Crop health; Quality; Protection Pasture and forage crops Cereals; Pulses and oilseeds Production systems Soil biology Soil quality Crop husbandry Soil tillage.
Ano: 2005 URL: http://orgprints.org/1479/1/recomp_2_subm.doc
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Natural regulation of Delia radicum in organic cabbage production Organic Eprints
Meyling, N.; Navntoft, S.; Philipsen, H.; Thorup-Kristensen, K..
In a field experiment, we evaluated effects of three different organic white cabbage-cropping systems (O1, O2, O3) on the cabbage root fly, Delia radicum, and its egg predators and pupal parasitoids over 3 years. The three systems all complied with regulations for organic production, but varied in external nutrient input and N-recycling, and were compared to a conventionally farmed control. One organic system (O3) included an intercropped strip of green manure between crop rows. Oviposition by D. radicum was generally not reduced in organic cropping systems. However, higher pupae/egg ratios were observed in the conventional compared to all organic systems, indicating that immature survival from oviposition to pupation was reduced under all the three...
Tipo: Journal paper Palavras-chave: Production systems; Soil biology; Vegetables; Biodiversity and ecosystem services.
Ano: 2013 URL: http://orgprints.org/22837/7/22837.pdf
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Olieræddike kan optage tabt nitrat fra 2,5 meters dybde Organic Eprints
Kristensen, H.L.; Thorup-Kristensen, K..
Nye forsøg viser at olieræddike har meget dybe rødder og kan opsamle nitrat fra 2,5 meters dybde. Hvis dybtrodede efterafgrøder placeres strategisk i sædskiftet, har man især på bedre jorder mulighed for at hente væsentlige mængder nitrat fra dybere jordlag.
Tipo: Newspaper or magazine article Palavras-chave: Nutrient turnover; Soil biology; Farm nutrient management; Air and water emissions.
Ano: 2003 URL: http://orgprints.org/7922/1/7922.pdf
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Plant-availability of catch crop S following spring incorporation Organic Eprints
Eriksen, J.; Thorup-Kristensen, K.; Askegaard, M..
Catch crops might reduce sulphate leaching and thereby increase the overall S use efficiency in crop rotations. At 2 experimental sites in Denmark (a sandy loam and a coarse sand) S uptake of catch crop species was measured. Furthermore net release of S following incorporation of this material (S contents 0.13-1.03%, C:S ratios of 40-329 and lignin content of 1-10.8%) was investigated in a pot experiment with spring barley in sandy soil. The catch crops showed huge differences in their ability to sequester S. The best catch crops (legumes on sandy loam), sequestered 10-12 kg S ha-1 and the poorest catch crops (ryegrass and sorrel on coarse sand), sequestered less than 3 kg S ha-1. The S mineralisation rates were highest for crucifers (57-85% of total S...
Tipo: Journal paper Palavras-chave: Nutrient turnover.
Ano: 2004 URL: http://orgprints.org/3173/1/3173.pdf
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Proteomic changes and endophytic micromycota during storage of organically and conventionally grown carrots Organic Eprints
LOUARN, Sébastien; Nawrocki, A.; Thorup-Kristensen, K.; Lund, O.S.; Jensen, O.N.; Collinge, D.B.; Jensen, B..
The physiological state of carrot roots during extended cold-storage is decisive for high postharvest quality. Wehave investigated differences in the proteome and micromycota of organically and conventionally grown carrots during six months of storage. The levels of only 15 proteins changed in level during storage. Proteins involved in cold stress adaptation and cytoskeleton components changed; these changes in specific protein levels occurred mainly during the first month demonstrating adaptation to storage conditions and that the carrots were subsequently stable, indicating stable carrot quality. The changes observed were similar in the two cropping systems. Using both biological isolation and a fungal PCR targeting the ITS region, we identified several...
Tipo: Journal paper Palavras-chave: Vegetables Crop health; Quality; Protection Post harvest management and techniques.
Ano: 2013 URL: http://orgprints.org/22846/7/22846.pdf
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Root development of beetroot, sweet corn and celeriac, and soil N content after incorporation of green manure Organic Eprints
Christiansen, J.S.; Thorup-Kristensen, K.; Kristensen, H.L..
Root development in beetroot (Beta vulgaris L. ssp vulgaris var. conditiva Alef.), sweet corn (Zea mays L. convar. Saccharata Koern.) and celeriac (Apium graveolens L. var. rapaceum Gaud.) was followed during two growing seasons with the aim of describing the root systems and nitrogen (N) utilisation of the three vegetables. The crops were grown after incorporation of green manure either in the preceding Autumn or Spring. Beetroot reached a final root depth of 1.55 – 1.8 m. For sweet corn, the final root depths were 0.6 and 0.9 m, and, for celeriac, 0.45 and 0.6 m in the two years, respectively. The simple measure of average root depth reflected the depth to which soil mineral N was depleted over the season by each of the three vegetables. Autumn...
Tipo: Journal paper Palavras-chave: Nutrient turnover; Crop combinations and interactions; Vegetables.
Ano: 2006 URL: http://orgprints.org/10135/1/10135.pdf
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Root growth and nitrogen uptake of carrot, early cabbage, onion and lettuce following a range of green manures Organic Eprints
Thorup-Kristensen, K..
An experiment was performed to study the significance of rooting depth of four vegetable crops on their utilization of green manure nitrogen (N). Rates of rooting depth development were estimated as approximately 0.2, 0.7, 1.2 and 1.2 mm day C)1 for onion, carrot, lettuce and cabbage, respectively. At harvest, onion and lettuce were found to be shallow-rooted with final rooting depths of only 0.3 and 0.6 m, respectively, whereas carrot and cabbage reached rooting depths of at least 1.1 m. The two deep-rooted vegetables increased their N uptake by 46, 24 and 7 kg N ha)1 when following winterhardy legumes, non-hardy legumes and rye, respectively; the equivalent responses by the two shallowrooted crops were 23, 9 and 15 kg N ha)1, respectively. Thus the...
Tipo: Journal paper Palavras-chave: Root crops; Vegetables; Air and water emissions; Composting and manuring.
Ano: 2006 URL: http://orgprints.org/7903/1/7903.pdf
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Root growth and soil nitrogen depletion by onion, lettuce, early cabbage and carrot Organic Eprints
Thorup-Kristensen, K..
Experiments examining root growth, the utilization of N and the effect of green manures were carried out on four vegetable crops. Large differences were observed both in rooting depth penetration rates, and in final rooting depth and distribution. Onion had a very low depth penetration rate, carrot an intermediate rate, and lettuce and cabbage showed high rates. A combination of depth penetration rates and duration of growth determined rooting depth at harvest. Therefore, lettuce, which had a very short growing season, had a shallow root system at harvest, whereas carrot with a lower depth penetration rate but a long growing season had deep rooting at harvest. The final rooting depth of the vegetables varied from approximately 0.3 m for onion to more than...
Tipo: Conference paper, poster, etc. Palavras-chave: Vegetables.
Ano: 2001 URL: http://orgprints.org/260/1/ActaHort_Root_growth_and.pdf
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Root pruning reduces root competition and increases crop growth in a living mulch cropping system Organic Eprints
Båth, B.; Kristensen, H.L.; Thorup-Kristensen, K..
Living mulch systems may decrease pest attacks. However, the below-ground competition from the living mulch may decrease the growth of the cash crop. Here growth of white cabbage in living mulch systems and in pure stands was compared. Root pruning of the living mulch increased the above-ground biomass of white cabbage, with two prunings giving higher cabbage yields than one. Below-ground growth and competition were examined by measuring root distribution in minirhizotrons and uptake of 15N placed at different soil depths. These studies showed that the ability of mulch species to compete for resources at depth was restricted by pruning.
Tipo: Conference paper, poster, etc. Palavras-chave: Crop combinations and interactions.
Ano: 2009 URL: http://orgprints.org/19583/3/19583.pdf
Registros recuperados: 26
Primeira ... 12 ... Última
 

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