Publikasjoner
NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.
2003
Sammendrag
Frukttrær er en langsiktig kultur, hvor angrep av planteparasittære nematoder kan føre til avlingstap og tredød. Nematodenes effekter på frukttrær beror av nematodeartenes oppformeringsevne og skadelighet på det aktuelle plantematerialet. Forekomst av nematoder og skuddtilvekst i en beplanting av moreller ved Ullensvang forskningssenter i Hardanger indikerte en viktig rolle for nematoder i vekstforstyrrelser. For å begrense nematodeskadene i frukthager må jordprøver tas ut senest året før planting. Ved høye nematodetettheter bør feltet brakkes eller tilsåes med underkultur som vil senke smittenivået før det plantes med nematodefritt plantemateriale.
Forfattere
S.H SalinasSammendrag
Nyttenematoder (insektpatogene nematoder: Steinernema og Heterorhabditis) kan brukes til mikrobiologisk bekjempelse av insektskadedyr. I dag finnes nematodene på markedet og brukes mest mot hærmygg i veksthus. I Norge er lite undersøkt om bruk på friland. I denne artikkelen omtales potensialet for bruk av nematoder mot rotsnutebiller (Otiorhynchus spp.) i jordbærfelt
Forfattere
Solveig Haukeland SalinasSammendrag
Nyttenematoder (insektpatogene nematoder: Steinernema og Heterorhabditis) kan brukes til mikrobiologisk bekjempelse av insektskadedyr. I dag finnes nematodene på markedet og brukes mest mot hærmygg i veksthus. I Norge er lite undersøkt om bruk på friland. I denne artikkelen omtales potensialet for bruk av nematoder mot rotsnutebiller (Otiorhynchus spp.) i jordbærfelt.
Forfattere
Tor J. Johansen Leikny ToftenSammendrag
Insektnetting satt opp som et 1,8 m høyt gjerde rundt felt med kålrot har begrenset angrepene av kålfluer betydelig i en forsøksserie i Nord-Norge. I gjennomsnitt var eggfangstene innenfor gjerdene redusert med 92 prosent i forhold til utenfor. Skadegraden ved høsting var 18 mot 66 utenfor og de salgbare avlingene godt over 4 tonn per dekar innenfor gjerdene mot ca. 1,5 tonn utenfor. Noen tilfeller med uakseptable sterke angrep innenforgjerdene kan trolig tilskrives feil montering av nettet eller turbulens på grunn av bygninger, trær e.l.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Zeliha Bahcecioglu Halvor B. GjærumSammendrag
Elleve rustsopparter, en som bare er bestemt til sp. (uten artsnavn), er beskrevet fra Anatolia i Lilleasia, Tyrkia. Fire arter er beskrevet som nye, viz. Puccinia malatyensis på Johrenia berytea, P. onosmatis på Onosma sericea, P. umbilicicola på Umbilicus erectus og P. yildizii på Echinophora tenuifolia. P. lactucarum på Scariola viminea og Uromyces eurotiae på Krascheninnikovia ceratoides er nye i tyrkisk rustflora. Petrorhagia alpina er en ny vertplanteslekt for Uromyces dianthi, mens Clinopodium vulgare ssp. arundanum er ny for Puccinia menthae i Tyrkia.
Forfattere
Christian Uhlig Alexander ZinkSammendrag
Mammalian herbivores generally influence soil properties of pastures significantly. However, rather little is known about impacts of Arctic Ungulates. The aim of this investigation was to identify possible changes in chemical soil properties due to different reindeer management systems on Finnmarksvidda: a) year-around used pastures in Finland, and b) winter pastures in Norway. Both managing systems are permanently separated by a fence, which was established during the 1950`ies. Iron podzol was the dominant soil type at both sides and fruticose lichen dominated dwarf shrub tundra was the typical vegetation type. However, lichen, plant and humus cover could vary greatly within the landscape. It was supposed that these differences were due to differences in grazing intensity. Based on a literature survey and field observations we therefore distinguished between the following four succession/ degradation stages I) thick (> 4 cm) lichen cover; II) grazed/ thin lichen cover (< 4 cm), but good plant cover; III) fruticose lichen cover almost absent, reduced plant cover and patches with exposed humus; IV) lichen, plant and humus cover almost absent, patches with bare mineral soil. According to this classification a 3 km2 large area along the boarder fence between Finland and Norway was mapped via a grid of sampling points. To compare soil chemical properties between the different succession/ degradation stages and different management systems, corresponding soil samples were taken from O, E and B-horizons at both side of the fence. Soil chemical parameters determined were pH, soil organic carbon (org.-C), Kjeldahl-N, C/N, cation exchange capacity (CEC), base saturation, and total and plant available P, Ca, Mg, K. During the presentation first results are presented with emphasis on potential impacts of reindeers on tundra ecosystems in general, and differences in pasture management in particular.
Forfattere
O. Janne KjønaasSammendrag
Det er ikke registrert sammendrag
Sammendrag
Nitrate leaching is often low from grasslands, primarily due to the long period of N uptake compared to arable crops. In the present paper we explore the combined effects of N input regime, soil type and climatic conditions through a combination of field lysimeter studies and simulation modelling of temporary grassland. A lysimeter consisting of eight 10´4´1 m individually drained cells was constructed in SW Norway, a region with a cool and wet marine climate. Six cells were filled with silty sand and two cells with coarse sand. The lysimeters were cropped first with barley for two years, followed by five years of grassland. Treatments included various combinations of N input (fertilizer, manure or both), and the results were analyzed by means of two coupled dynamic simulation models (CoupModel: a heat- and water transport model, SOILN_NO: a soil nitrogen model). The models were further used to assess a scenario with a more continental climate (somewhat cooler and dryer). All treatments resulted in a net export of N, with N amounts removed by harvest ranging between 121 and 139% of that applied. Measured N yield from the treatment receiving manure only was almost as high as that from the treatment receiving fertilizer only, even though it received on average about 80 kg ha-1 less inorganic N for which possible explanations are discussed. Nitrogen losses through leaching were in the range of 5-23% of the N input, and soil type had a greater effect than source of N input. The inorganic N fraction of the leachate was 71-82% of the total N, and 98% of this was nitrate. The models gave reasonable simulation of N yields as well as of the timing and magnitude of nitrate leaching from the different treatments. They also clearly illustrated the importance of plant uptake of N in early spring and late autumn, in order to reduce the risk of nitrate leaching. The scenario using weather data from a cooler and dryer region showed a large decline in plant uptake of N outside the main cropping season, but simulated nitrate leaching was nevertheless significantly lower. With this scenario, precipitation was only 50% of that at the actual experimental site, and the lower temperatures during autumn and winter reduced net mineralization of soil organic N significantly. Thus, the reduction in precipitation and net mineralization of soil organic N apparently more than outweighed the effects of shorter growing season in the continental climate sc.
Sammendrag
Det er ikke registrert sammendrag