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.
2011
Abstract
We overview the main goals and results of ongoing research on carbon cycle of agricultural lands in Hungary. This multi-scale and multi-objective research aims at a better understanding of CO2 exchange between agricultural ecosystems and the atmosphere. The integration of field measurements, laboratory measurements and remote sensing makes it possible to distinguish between and to evaluate the importance of different biotic and abiotic drivers of CO2 exchange on multiple spatial and temporal scales. Spatially representative data based on remote sensing provides invaluable information to constrain regional scale estimations of carbon balance of agricultural lands. The main three pillars of carbon cycle research in our case are field and laboratory measurements of soil respiration, field measurements of ecosystem CO2 fluxes (using the eddy-covariance method), and remote sensing based modelling of carbon cycle components. Measurement sites include various agricultural fields: crop rotation, peach plantation, croplands of a mixed agricultural landscape. Heterogeneous agricultural vegetation is a typical land cover type that occupies major parts ofHungary.
Abstract
Norwegian lamb meat production is mainly based on free grazing in mountainous pastures during the summer. Prior to slaughter in the autumn, some lambs not big enough for slaughter are finished on e.g. cultivated pastures. This study looked at the feed quality of different forages, and the effect on lamb meat quality. Lambs grazed on mountain pastures at Kvaløya in Northern Norway (69°N) and Sør-Fron in Mid Norway (58°N) in 2007, and a subgroup at each location was finished on cultivated pastures for 6 weeks prior to slaughter in September. The fiber content was significantly higher in the cultivated pasture in Mid Norway compared to the mountain pasture while no differences between pastures in Northern Norway were found. In Mid Norway the content of polyunsaturated fatty acid (18:3) was significantly higher in meat from lambs grazing the mountain pasture compared to lamb grazing the cultivated pasture. For Northern Norway, the opposite pattern was observed. The higher 18:3 content may be attributable to lower fiber content at the mountain pasture. In our study, there appears to be an effect of fiber content on the fatty acid composition in lamb meat.
Abstract
Norwegian lamb meat production is mainly based on free grazing in mountainous pastures during the summer. Prior to slaughter in the autumn, some lambs not big enough for slaughter are finished on e.g. cultivated pastures. This study looked at the feed quality of different forages, and the effect on lamb meat quality. Lambs grazed on mountain pastures at Kvaløya in Northern Norway (69°N) and Sør-Fron in Mid Norway (58°N) in 2007, and a subgroup at each location was finished on cultivated pastures for 6 weeks prior to slaughter in September. The fiber content was significantly higher in the cultivated pasture in Mid Norway compared to the mountain pasture while no differences between pastures in Northern Norway were found. In Mid Norway the content of polyunsaturated fatty acid (18:3) was significantly higher in meat from lambs grazing the mountain pasture compared to lamb grazing the cultivated pasture. For Northern Norway, the opposite pattern was observed. The higher 18:3 content may be attributable to lower fiber content at the mountain pasture. In our study, there appears to be an effect of fiber content on the fatty acid composition in lamb meat.
Authors
Vibeke LindAbstract
Norwegian lamb meat production is mainly based on free grazing in mountainous pastures during the summer. Prior to slaughter in the autumn, some lambs not big enough for slaughter are finished on e.g. cultivated pastures. This study looked at the feed quality of different forages, and the effect on lamb meat quality. Lambs grazed on mountain pastures at Kvaløya in Northern Norway (69°N) and Sør-Fron in Mid Norway (58°N) in 2007, and a subgroup at each location was finished on cultivated pastures for 6 weeks prior to slaughter in September. The fiber content was significantly higher in the cultivated pasture in Mid Norway compared to the mountain pasture while no differences between pastures in Northern Norway were found. In Mid Norway the content of polyunsaturated fatty acid (18:3) was significantly higher in meat from lambs grazing the mountain pasture compared to lamb grazing the cultivated pasture. For Northern Norway, the opposite pattern was observed. The higher 18:3 content may be attributable to lower fiber content at the mountain pasture. In our study, there appears to be an effect of fiber content on the fatty acid composition in lamb meat.
Abstract
Utilizing animal slurry to produce biogas may reduce fossil fuel usage and emissions of greenhouse gases. However, there is limited information on how the recycling of digested slurry as a fertilizer impacts soil fertility in the long run. Anaerobic digestion decreases the content of organic matter in the slurry and organic farmers are concerned that this will deplete soil organic matter pools. This will be studied in the SOILEFFECTS project, initiated in 2010 at an organic research farm in Tingvoll, Norway. A local biogas plant produces anaerobically digested slurry, to be compared with non-digested slurry in perennial ley and arable crops. Effects on crop yields, and a range of soil characteristics will be measured
Authors
Margarita Novoa Garrido Lise Aanensen Hans Jørgen S. Larsen Søren K. Jensen Håvard SteinshamnAbstract
E vitamin er nødvendig for drøvtyggere for å opprettholde et velfungerende immunsystem, høy reproduksjonsnivå, og god melk- og kjøttkvalitet. Innholdet av antioksidanter i råmelken påvirker absorpsjonen av antistoffer hos nyfødte kalver. Selen innholdet i jord og dermed hjemme dyrket grovfôr kan være fattig på selen. Hvis grovfôret også er fattig på E vitaminet, som samhandler sine biologiske effekter med selen, kan underforsyning lett oppstå. Derfor blir rasjonene til drøvtyggere supplert med syntetisk produsert E vitamin for å sikre tilstrekkelig inntak av E vitamin. Det er imidlertid kjent at syntetisk E vitamin består av 87,5 % molekyler med ikke-naturlig konfigurasjon og som biologiske ikke er like effektiv. Av denne grunn er det viktig å finne alternative naturlige vitamin- og antioksidantkilder som er billig, bærekraftig å utvinne og enkle å håndtere, spesielt med tanke på økologisk husdyrproduksjon, men også for tradisjonell husdyrproduksjon. Det ble derfor gjennomført et forsøk med drektige søyer for å teste tang og naturlig E vitamin som mulige kilder for E vitamintilskudd og deres effekt på dyrehelsen hos søyene og avkommene.
Authors
Tor LunnanAbstract
Free-range grazing on mountain pastures is common practice for sheep and cattle farming in southern Norway. Investigations have shown that animal growth and milk production decrease towards the end of the grazing period. This has been explained by the decrease in forage quality and quantity. In two seasons, three grass species and Carex spp. were sampled at four locations early or late in the summer. Forage quality was determined by NIRS with a broad calibration for grasses. The energy value was highest in Agrostis capillaris and Avenella flexuosa, followed by Deschampsia cespitosa and Carex spp. The energy value decreased through the season; however, A. flexuosa kept a high energy value even in early autumn. The protein value declined steadily through the grazing season. Avenella flexuosa was lower in protein than the other species, especially early in the season. This investigation indicates that the decline in energy value is not the main reason for declining animal response at the end of the grazing season. Factors such as low forage intake and low content of protein might be more important. Keywords: quality, grazing, Avenella flexuosa, Deschampsia cespitosa, Agrostis capillaris, Carex
Abstract
Fusarium graminearum causes head blight disease in wheat, and to help understand the infection process we studied global gene expression of F. graminearum in a time series of 24 to 196 hours after inoculation, compared to a water control. The infection is rapid and already after 48h over 4000 genes is expressed. The number of genes expressed increased over time up to 96h (>8000 genes), and went down again 144h and 192h post inoculation. After subtraction of genes found expressed on complete media, during C and N starvation, and on barley, only 355 were found exclusively expressed in wheat, mostly ones with unknown function (72,6%). These were mainly found in SNP enriched islands on the chromosomes, suggesting a higher evolutionary selection pressure of wheat specific genes. The annotated genes found were enriched in functional groups involved in allantoin and allantoate transport, detoxification, nitrogen, sulfur and selenium metabolism, secondary metabolism, carbohydrate metabolism and degradation of polysaccharides and ester compounds. Several putative secreted virulence factors were also found expressed in wheat.
Abstract
Pieces from the stem, approximately 1.5 m above the trunk base, from two Norway maple (Acer platanoides) trees were collected in March 2010 in a forest in Stavanger, a city on the southwestern coast of Norway. The trees showed dieback symptoms in the crown and had bleeding canker wounds on the stems. Phytophthora plurivora had been isolated from the trunks in 2009. At JKI the wood samples were cut into sections, and a detailed procedure was followed for fixation, dehydration, preinfiltration, infiltration, polymerization, and mounting. The mounted histoblocs with the specimen were removed from the histoforms, and a rotary microtome was used for preparing thin sections which were placed on glass slides for microscope examination. Examination in light microscope revealed that the cells in the vascular system had collapsed. Phytophthora-like hyphal growth was found in and between wooden cells, but not in the bark. Since P. plurivora was isolated from the sample, we may conclude that the hyphae belonged to that pathogen. Also epifluorescence studies were carried out, and we found non-septated hyphae in the rays, further indicating the presence of P. plurivora in the wood tissue.
Authors
Hans Ragnar Norli Geir Kjølberg Knudsen Marco TasinAbstract
Kairomones intersecting host searching females is an attractive method for species-specific pest control. Apple fruit moth, Argyresthia conjugella, is a major pest of apples in Fennoscandia. The severity of the attacks on apple happens as a response to large scale masting in the moths principal host rowan, Sorbus aucuparia. Co-occurrence of volatile compounds in rowan and apple is suggested to facilitate the forced host shift. The apple fruit moth responds to odour from its principal host with upwind orientation in a wind tunnel. Host responding apple fruit moths have high plasticity to blend ratios suggesting why a specialist insect can locate alternative host during intermast years and damage apples. However, even with all host compounds present, distortions of blend ratios seriously jeopardize upwind orientation in laboratory bioassays. In a combined approach with wind tunnel bioassays and field trapping, we have now identified a seven-component blend which is highly attractive for gravid female apple fruit moths. The new blend is especially attractive in apple crops, showing high odour competition compared to the secondary host. Verification of the blend in monitoring to achieve increased precision of pesticide sprays, establishment of economic damage thresholds and mass trapping is ongoing.