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.
2024
Forfattere
Sarah Lise HjelleSammendrag
Closed landfills have received increased attention in recent years due to their environmental impacts and challenges related to construction on or near such areas. In the past, waste management was less regulated, and there were less structural requirements for the design of landfills as there are today. This thesis is a research project within earthresQue and aims to increase the knowledge about older landfills in Norway. The Brånåsdalen landfill in Lillestrøm municipality was in operation from 1971 to 1991, where gas and settlement damage have been the main issues following the closure of the landfill. In this study, a combination of various methods was used to map the top cover and sealing layer, as well as the boundaries of the landfill. Electrical resistivity tomography (ERT) is a geophysical method used to investigate lateral and vertical changes in resistivity or conductivity in the ground, providing information about the electrical properties of different types of materials. In several areas, it was not possible to distinguish between the top cover and the sealing layer with ERT, even though field observations showed a clear layering. A possible reason for this could be that the top cover is thin, varying between 9 and 40 cm, and an average of 20 cm. Another reason could be that the distance between the electrodes is too large and with the resolution being too low. The thickness of the sealing layer varies greatly, and the depth down to the waste masses is between 1.5 to 6 meters. Overlapping resistivity values between the top cover, the sealing layer, and the waste masses make it challenging to distinguish the layers. Additionally, no clear distinction is observed between the inside and outside of the landfill in the horizontal direction. The sealing layer appears to be more heterogeneous than the top cover based on grain size analysis and statistical analysis. Infiltration measurements showed that the saturated hydraulic conductivity (Ksat) has spatial variations and that there is no difference in Ksat between the top cover and the sealing layer. The values vary both within and between different locations, where the median for the hydraulic conductivity in the top cover was 4,0 ∗ 10−5 m/s and in the sealing layer 6,8 ∗ 10−5 m/s. The top cover has a satisfactory grain size distribution and an average content of organic matter of 4%, which means that the soil can maintain good growing conditions. Because the soil layer is thin, it does not fall within what is recommended under current legislation with a thickness of 1 meter, which may result in the sealing layer being less protected and more susceptible to erosion.
Forfattere
Elias GarvikSammendrag
The Norse built their hulls from oak boards hewn from cleaved or ‘rived’ logs. We know this through artworks and texts as well as archaeological finds describing the ships as well as their construction from the latter half of the early-medieval period. However, we know summarily little when it comes to the pre-production of hewn boards. I ask, - How could the Norse have possibly cleaved? - Which properties in white oak affect cleaving? - Which simple truths can be found of cleaving. Which direction of cleaving is best for oak? This is done by showcasing the differences in cleaving from the top, side, and bottom of a series of white oak logs. Namely why cleaving from each direction fails. To summarize the results. Cleaving from the top shines in cases where there is a large difference in the diameter at the top and bottom of the log. Cleaving from the side can act as a mitigator in the case of knots or to pierce directly through a knot or burl. Cleaving from the top or bottom falls more naturally in the cases where the pith is off-centre. With a log bent like an arch, cleaving from the side fell more naturally. The direction of the cleave ought to be thought of less as an immutable truth and more of as another tool to extract as many boards from a log as possible. We found that no direction of cleaving was inherently better in all scenarios. It is a case of risk-mitigation, which benefits from taking a thorough look at the log and making an informed choice. In cases where the angle of the twisting fibres of a log is significant, all cleaving directions struggle and fail, in cases where there are few natural faults, cleaving from all sides succeed.
Forfattere
Einar Lyche LebesbyeSammendrag
Land-based wind power is considered one of the most applicable sources of renewable energy for the future. While cost effective, the knowledge of ecological consequences associated with construction and operation is limited. This thesis investigates how vegetation and cervid animals at Lista Wind Park were affected by its construction and operation. Vegetation data in revegetated and control plots were compared over a twelve-year period and tested for variation in species richness, species diversity and foliar coverage. Dispersal of alien species, as a result of infrastructure construction, was also investigated. Cervid habitat use was mapped one year before, during construction and several different years after the wind park was set into operation. This data was considered unreliable due to inconsistency in sampling circumstances and lack of calibration between observers, and not analysed further. Rather, inter-observer discrepancies in species identification were investigated. Vegetation in revegetated plots seems to converge towards control plots after twelve years. Differences in species richness, species diversity and foliar cover are no longer significant. However, models fail to account possible variations due to climate. The construction of the wind park resulted in dispersal of alien species. In general, experienced observers had trouble identifying species though photographs of feces, only being certain in ca. 50% of the cases. In cases where observers were certain, species ID was different compared to another observer in 19% of the cases. More studies are needed to determine land-based wind powers ecological consequences, especially on cervids.
Forfattere
Elise Lyng MonssenSammendrag
Wildlife-train collisions are a widespread issue, leading to significant costs to society, reduced animal welfare and potential impacts on species' population sizes. Understanding how ungulates respond to oncoming trains and what affects their detectability is crucial for developing effective mitigation strategies. Building upon the work of Bhardwaj et al. (2022), this study investigates how various factors influence flight behaviour in fallow deer (Dama dama), roe deer (Capreolus capreolus) and moose (Alces alces), as well as wildlife detection from the train driver's perspective. By utilizing films from driver-activated scare systems (DASS) mounted on the front windshield of trains on Norwegian and Swedish railways, this study offers insights into both wildlife reactions and the viewpoints of train drivers. Based on approximately 1000 observations of ungulates, each individual encounter with trains was analysed in relation to railway features, train speed, the train driver’s use of typhoon warning, the ungulates’ location within the terrain and biotic and abiotic factors in the surrounding landscape of the railway. Detection distance and flight initiation distance (FID) was calculated based on the video footage. The results showed that with increasing distance from the railway tracks, ungulates in total were less likely to flee from an approaching train and more likely to increase their FID. Generally, there was a higher probability of flight when the typhoon was used to warn the ungulates, but the effect of this signal was not significant in any of the separate analyses on each species alone. There was also a higher likelihood of flight during dusk/dawn. Flight behaviour of fallow deer was significantly influenced by herd size, with a greater likelihood of flight in smaller groups separated from a large herd. In contrast to roe deer and fallow deer, moose were significantly affected by train speed, with flight likelihood and FID decreasing with increasing speed. All species showed a significantly higher probability of flight across track with closer distance to the track, and in areas where the rail embankment was covered by vegetation with exception of roe deer. Additionally, ungulates in total had a higher probability of an early flight, before detected by the train driver, when visibility was obstructed by vegetation, terrain and curvature of the railway. Lastly, detection distance from the train driver’s perspective was significantly obstructed by vegetation along the railroad embankment. Further studies are suggested on a warning system that could be activated before the animals are detected by the train driver to increase animals’ FID, alongside the implementation of night vision cameras for improved detection of animals during nocturnal hours.
Forfattere
Lars Sandved DalenSammendrag
En viktig del av vårt samfunnsoppdrag er å kommunisere vår kunnskap og delta i samfunnsdebatten. Kronikken er et godt verktøy. Forfatteren er fagperson som bidrar med sin fagkunnskap. En levende og åpen samfunnsdebatt krever at dokumentasjon og oppdatert kunnskap blir gjort tilgjengelig for allmennheten. Og fagpersoner bør delta – med sin kunnskap og fakta. Kunnskap og fakta har imidlertid i flere sammenhenger kommet i miskreditt (fake news, klimadebatten), og det vil være av stor betydning at fagpersoner og forskere evner å nå frem med sin kunnskap til landets innbyggere. Bli bedre til å skrive og formidle forskningen din. Kommunikasjonsrådgiver Lars Sandved Dalen ved NIBIO har siden 2010 hjulpet forskere og fagpersoner med å få over 100 kronikker og debattinnlegg på trykk i norske aviser. I 2023 fullførte han det nyopprettede, fireårige deltidsstudiet i journalistikk og sakprosa ved Institutt for journalistikk og mediefag, OsloMet, med en masteroppgave om kronikken som sjanger. Sammen med forfatter og journalist Dag Kullerud skal Lars Sandved Dalen skrive en lærebok/håndbok om kronikken. Foredraget gir et unikt innblikk i kronikkens utvikling fra den danske avisa Politikens første kronikk i mai 1905 til dagens debattjournalistikk - med er særlig blikk på utviklingen de siste 50 år i de norske avisene Aftenposten, Dagbladet og VG. I tillegg får du de beste kronikkskrivetipsene fra Norges fremste debattredaktører - blant annet Erik Tornes i Aftenposten, Hans Petter Sjøli i VG, Tollef Mjaugedal i Klassekampen, Vidar Ivarsen i Dagens Næringsliv og Trønderdebatts Snorre Valen - og spesialoppfølging slik at nettopp du får din tekst på trykk akkurat der du ønsker.
Forfattere
Lars Sandved DalenSammendrag
Kursholder er kommunikasjonsrådgiver Lars Sandved Dalen ved NIBIO. Han har siden 2010 hjulpet forskere og fagpersoner med å få over 100 kronikker og debattinnlegg på trykk i norske aviser.
Forfattere
Hanna Ellisiv KringstadSammendrag
Potato haulm killing is a prevalent practice in the global potato production to ease vine management, aid tuber maturation and remove late blight inoculum. EU’s ban of the herbicide diquat (e.g. in the product Reglone) to kill potato haulm, has left the producers and scientists in need to find alternative measures. Five different doses of hot water were tested in combination with mechanical haulm flailing, to study their ability to kill potato haulm in an open field in Innlandet, Norway. Remaining fresh stem and leaves, and number of plants with regrowth, were observed visually 7 times over 21 days following the hot water treatment. There were found significant differences in fresh leaves and stem over time when comparing mechanically flailed plants to the naturally senesced counterparts, but no added effect in senescence was found by adding any of the doses of hot water. Quality analysis of the harvested tubers considering yield, size distribution, green tubers, abrasion injury and disease, found no effect of the different treatments on any of the quality parameters.
Forfattere
Helene Leirset TysdalSammendrag
In a world with war, hunger and increasing expenses, food production is an important aspect. Every country has a need and a responcibility to be able to produce enough food for its own people. Wheat is an important crop that can contribute to increased self sufficiency in Norway. The Norwegian milling industry largely controls the proportion of domestic wheat to be used for milling. Because of that they have imported a lot of the wheat needed to produce flour in the past. In the cases where Norwegian wheat have been used, it has mostly been spring wheat. Winter wheat has a high yield potential, and can ve important to utilize to achive goals for increased self-sufficienct fot the Norwegian agriculture, but more research is required to meet the milling industries requirements. Winter wheat production may be an important step in this process. This master thesis aimes to reachers how split nitrogen fertilication affects yield components and protein in the grain. As well as how N-sensor measurments at heading and flowering can be an effective tool to guide the farmers. Five fertilization strategies, four locations and tre variaties was used to reachers the effect of split nitrogen fertlization. Each location had three repetitions and every repition included every possible combination of fertilization strategy and variaty. Plant nitrogen level was monitored during the growing season to predict the protein content at harvest. The results showed that for protein percentage, the fertilization regiment is the most important aspect, hereunder total nitrogen content and the distributio between the different applications. Giving 8 kg of nitrogen at the first application and 6 kg of nitrogen at the second application gave a significantly higher protein content compered to giving 14 kg of nitrogen at the first application and nothing at the second. To get a higher yield the most important aspect is the winter wheat variety and Kuban gave a significantly higher yield than Bernstein and Ellvis. N-sensor measurments and measurments of the real nitrogen uptake was done at heading and flowering. The N-sensor measurmetns underestimated the nitrogenuptake especially in field with drought. Regression analysis found that 2/3 of the observed variation could be explained by the model at z49 and z65. More research and a bigger dataset is thereby needed to get a better model.
Forfattere
Erlend Podhorny ØklandSammendrag
Denne masteroppgaven består av en teoridel og en forsøksdel med egne undersøkelser. Teoridelen tar for seg temaer relatert til grovfôr og drøvtyggerernæring. Grovfôr består av ulike fraksjoner, deriblant strukturelle karbohydrater som hemicellulose og cellulose. Disse kan fordøyes av drøvtyggere gjennom fermentering i formagene, hvor mikrober bryter karbohydratene ned til flyktige fettsyrer. Grovfôr kan konserveres gjennom ensilering, hvor melkesyrebakterier fermenterer sukker i graset til melkesyre, som senker pH og gjør fôret lagringsstabilt. For å øke sannsynligheten for vellykket ensilering kan ensileringsmidler tilsettes, deriblant fibrolytiske enzymer som bryter ned hemicellulose og cellulose. Målet med fibrolytiske enzymer er å frigjøre sukker til melkesyrebakterier, i tillegg til å øke fordøyeligheten av grovfôret. Forsøksdelen er utformet som en artikkel, hvor formålet var å undersøke effekten av maursyre og fibrolytiske enzymer på fordøyelighet av ensilert gras. Timotei (Phleum pratense) ble høstet ved et sent utviklingstrinn og behandlet med maursyre og/eller enzymer før ensilering. Enzymene som ble testet var hemicellulase, cellulase, Cellic CTec2 og laccase. Etter ensilering ble fordøyelighet av tørrstoff (TS), organisk stoff (OS) og nøytralløselig fiber (NDF) undersøkt med ANKOM DaisyII inkubator. Fordøyelighet av NDF ble beregnet både som tap av native NDF (NDF som er analysert for hver enkel behandling) og som tap av totalt NDF basert på ubehandlet surfôr (“originalt” innhold av NDF i ubehandlet surfôr ble brukt som basis for forsvinningsgrad) for å ta hensyn til NDF som ble nedbrutt under ensilering. Innhold av NDF var signifikant (p<0.05) lavere for behandlinger med enzymer, enn behandlinger uten enzymer. Selv om maursyre ikke reduserte NDF signifikant, var det nær en trend (p=0.1003). Fordøyelighet av TS og OS økte signifikant (p<0.05) både ved bruk av enzymer og maursyre. Enzymer reduserte den potensielt nedbrytbare fraksjonen av TS og OS og økte den løselige fraksjonen, begge signifikant (p<0.05). Fordøyelighet av native NDF ble redusert (p<0.05) ved bruk av enzymer, men fordøyelighet av total NDF ble økt (p<0.05). Maursyre reduserte ufordøyelig NDF signifikant (p<0.05) for native NDF og total NDF sammenlignet med hvis maursyre ikke ble brukt. Forsøket som helhet bekreftet hypotesen om at bruk av enzymer og maursyre kan øke fordøyeligheten av grovfôr.
Forfattere
Emma SkogstadSammendrag
In cereal production plant pathogens cause yield losses, and management strategies for controlling them are important. Cover crops as a part of the cereal production have beneficial properties for the soil health, can increase the biological diversity in the fields, and the soil structure can be improved, additionally cover crops can reduce soil erosion. Therefore, this thesis argues that implementing cruciferous plants as part of the cover crops have the potential to reduce plant pathogens. Cruciferous plants used as cover crops have shown to reduce plant pathogens survival both in laboratory and field plots. The suppression is due to the volatile glucosinolate (GLS) and isothiocyanate (ITC) content cruciferous plants. As a part of a project at NIBIO Ås, an in vitro experiment with allyl ITC were done to look at the effect on survival of Heterodera avenae, Fusarium graminearum and Microdochium nivale, with increasing allyl ITC concentration. Also, a closed jar experiment was conducted to look at the effects of cruciferous plants on suppression of survival of Heterodera avenae and Fusarium graminearum. The aim of the in vitro experiment was to see at which concentrations of allyl ITC that suppressed fungal growth of F. graminearum and M. nivale and hatching of the cereal cyst nematode H. avenae. The EC50-values of the F. graminearum isolates 200 630, 201 196 and 202 058, were 6.36, 9.50 and 7.62 mg/L respectively. EC50-values of M. nivale isolates 200 136, 200 231 and 202 786, were 8.60, 10.83 and 10.27 mg/L respectively. For H. avenae, the EC50-value was at 5.66 mg/L. This demonstrates a differentiation of EC50-values between nematodes and fungi, but also between fungal species and fungal isolates. A closed jar experiment was conducted to see if incorporation of cruciferous plants in soil may affect the survival of H. avenae and F. graminearum. Two different time exposures in jars with either two or eight weeks of exposure in jars, were performed. After treatments in jars, the cysts were given either a diapause or no diapause treatment. The total number of eggs and J2 were significantly lower for cysts exposed for eight weeks in jars compared to two weeks, but the total number of eggs and J2 were almost equal for diapause and no diapause. The number of hatched J2 (15°C) for cysts with diapause treatment had significantly higher number of J2 than no diapause treatment. Also, the number of hatched J2 were significantly higher for two weeks exposure in jars compared to eight weeks. The mycelial growth from F. graminearum on oat spikelet incorporated in soil with plant material was not different from untreated.