|
|
|
Registros recuperados: 26 | |
|
|
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 |
| |
|
|
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 |
| |
|
| |
|
|
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 |
| |
|
|
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 |
| |
|
|
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 |
| |
|
| |
|
|
Navntoft, S.; Thorup-Kristensen, K.; Eilenberg, J.; Kristensen, K.; Meyling, N.V.. |
Organic farming should support high levels of biodiversity and rely on biological pest control by natural enemies. Management of organic systems must comply with specific regulations, but within this frame management is not clearly defined. In experimental cabbage fields we studied ground beetle abundance and diversity in three different organic farming systems (O1, O2, and O3). All systems complied with regulations for organic production, but relied on either high (O1) or low (O2 and O3) external input of nutrients. The systems O2 and O3 also included green manures, and in O3 strips of green manure were left between crop rows. A conventional system was included as control. Only organic systems O2 and O3 showed benefits for ground beetles, but in different... |
Tipo: Journal paper |
Palavras-chave: Biodiversity and ecosystem services. |
Ano: 2011 |
URL: http://orgprints.org/19303/4/19303.pdf |
| |
|
|
Thorup-Kristensen, K.. |
I økologisk dyrkning er tilgængeligheden af næringsstoffer i jorden ofte begrænset, og da planterne alligevel skal være i stand til at optage næringsstoffer, så de får en god vækst, har de økologiske planteavlere brug for sorter med ekstra kraftigt rodsystem. I forskningsprojektet RoCo har vi derfor undersøgt, om der er sortsforskelle med hensyn til rodvækst, som gør nogle sorter bedre egnede til økologisk dyrkning end andre. Og det har entydigt vist sig at være tilfældet. Forsøgene tyder på, at økologiske planteavlere kan få meget ud af at være omhyggelige med sortsvalget. |
Tipo: Newspaper or magazine article |
Palavras-chave: "Organics" in general. |
Ano: 2015 |
URL: http://orgprints.org/28213/1/28213.pdf |
| |
|
|
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 |
| |
|
|
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 |
| |
|
|
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 |
| |
|
| |
|
| |
|
| |
|
|
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 |
| |
|
|
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 |
| |
|
| |
|
|
Båth, B.; Kristensen, H.L.; Thorup-Kristensen, K.. |
In intercropping systems with a cash crop and a living mulch intercrop, competition between the cash crop and the intercrop (the living mulch) often reduces the yield of the cash crop. This project investigated (1) the influence of root pruning of living mulches on aboveground biomass of white cabbage. Below-ground growth and competition were examined by measuring (2) root distribution in minirhizotrons and (3) uptake of 15N placed at different soil depths. Two field experiments were carried out at the Aarslev Research Centre in Denmark. 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/19584/1/Poster_(2)_rootrap.ppt |
| |
|
|
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 |
| |
Registros recuperados: 26 | |
|
|
|