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.
2007
Forfattere
Ronald Bjøru Gunn Elin FedreheimSammendrag
Being a farmer in Northern Norway is challenging in many ways. In the last 20 years a greater attention has been given on area conservation, also influencing the farmer in many ways. In order to reach IUCN"s goal of conserving 15 % of the land area in Norway, it is necessary to conserve also private property as national parks. Increasing the conservation of outfields affects property owners in many ways; the conservation regulations define which initiatives can be taken in an area, the use of the area for forestry might be regulated, the national park status might attract even more people. All of these factors are mentioned as considerations regarding area conservation in Norway. In this paper we will present some preliminary results from the project Protected Areas as Resources for Coastal and Rural Business Development (PROBUS). The research question in this paper will be the following: How can farmers continue their activities or create new activities in conserved areas in Northern Norway? Some of the themes addressed will then be the different incentives relevant for farming in conserved areas, formal regulations that regulate farming in conserved areas, the possibilities for supplementary activities related to tourism and outdoor activities, and the interplay between the possibilities and the limitations with farming in conserved areas.
Forfattere
Tor Håkon SivertsenSammendrag
The topography of the earth influences the movements of parcels of air in the atmosphere. Wind systems blowing across mountain ridges sometimes excite stationary gravity wave systems behind and above ridges witrh a breath of about 10 km. The conceptual discussion in this paper is connected to the transport of wave energy in stationary gravity waves and stationary gravity inertia waves , where there are discontinuities in the parameters describing the vertical stratified atmosphere. The discussion is closely connected to two theorems by Eliassen and Palm (1961) showing that the vertical flux of wave energy is conserved throughout the atmosphere for a great class of systems. But the boundary conditions used by Eliassen and Palm (1961) in the gravity wave systems connecting the vertical layers in situations with discontinuities do not cover all possible physical situations of interest.
Forfattere
Anne Falk Øgaard Tore KrogstadSammendrag
In most of the profiles on clay soil there were high values of P-AL in the deepest layers. This was true also for the uncultivated soil, where the P-AL values were as high as 100-120 mg P kg -1. In the deepest layers of cultivated soil, P-AL values of 150-200 mg P kg-1 were observed in some of the profiles. These high values are probably a result of transport of P rich particles from the topsoil through macropores. This is supported by a significant positive relationship between P-AL in topsoil (0-10 cm) and the average P-AL at 80-100 cm depth, and a higher P-AL to Ca-AL ratio in the cultivated than in the uncultivated soils in deep profile layers. The P-CaCl2 concentration in the subsoil was zero or close to zero in all the profiles, despite high P-AL values. Increasing pH with depth influences the distribution of P among the different P fractions.
Sammendrag
A series of field trials combining cultivars with different levels of resistance to Phythophtora infestans and different haulm killing methods was conducted in 1997, 1998 and 1999 to assess the contamination potential of the haulm. In addition, the frequency of tubers with late blight was assessed after harvest and storage, combining effects of pretreatment infection, infection by the haulm at harvest and the development of the disease during storage. Haulm killing was performed by diquat (200, 400, 600 g a.i. ha-1), half cutting of the haulm in combination with diquat (100, 200, 300 g a.i. ha-1) or full cutting of the haulm. In those treatments where haulm killing was performed purely chemically the haulm remnants" contamination potential tended to increase at reduced doses. Full mechanical destruction gave as low a contamination potential as application of the full dose of chemical haulm killer. However, there were no consistent differences between the haulm killing treatments in the frequency of blighted tubers after harvest and storage. This indicates that the input of chemical haulm killers may be reduced. There was a large difference between years in tuber blight after harvest and storage, which confirms that climatic factors are of major importance for tuber infection. The large difference found between the cultivars in the frequency of tuber blight indicates that tuber resistance should be an important part of integrated late blight disease management.
Forfattere
Hans OvergaardSammendrag
Knowledge of factors that influence oviposition behavior of malaria mosquitoes is critical to vector control measures aimed at larval habitat modifications and source reduction. Anopheles minimus s.l., an important malaria vector in Southeast Asia, generally breeds in clear, unpolluted water along shaded grassy edges of slow-moving streams. The objective of this study was to determine the influence of vegetation and plant structure on An. minimus s.l. ovipositing females. Twenty gravid female mosquitoes per replication were given a choice to lay eggs in bowls surrounded by different combinations of bare soil, grasses, small-leaved plants, and large-leaved plants. An. minimus s.l. females generally preferred to lay eggs in bowls with vegetation. A significantly higher number of eggs were found in bowls with small-leaved plants compared to bowls with grasses (P large-leaved plants > grasses > soil. Further studies are needed to determine the possible roles of plant structure and factors such as semiochemicals in the different species of the An. minimus species complex. Knowledge of female oviposition behavior is essential for the development of locally adapted approaches to source reduction and breeding site interventions.
Forfattere
Nina Opstad Arnfinn Nes Finn Måge Bjørn HagebergSammendrag
Two-year-old blackcurrant plants cv. Ben Tron were planted in 1991 to investigate long-term effects of seven fertilization strategies. Broadcast fertilization was given in spring and autumn, fertigation from May until August, or a combination of fertigation and broadcast fertilization. Three fertilizer rates were used, and the amount was increased three times during the trial because of low mineral content in the leaves and insignificant yield response. Yield parameters, macro nutrient content in leaves and content of soluble solids in fruit juice were recorded over 11 years. The variation between years was significant for all parameters recorded, but the fertilization strategies had only a minor effect over time. Content of macro nutrients in leaves was low compared to recommended values, and did not respond significantly to increasing fertilizer amounts. Yield decreased with plant age. Frost reduced yield in at least two years, but few significant correlations with precipitation and temperature were found. A good water access seems to be important for a stable fruit yield, while precipitation during flowering is likely to reduce yield because of fruit drop.
Forfattere
Trygve S. Aamlid Nicholas JarvisSammendrag
Soil water repellency (hydrophobicity) is a common problem on sand-based golf greens. Due to this phenomenon, soil water may percolate as "finger flow" rather than uniformly through the soil profile. The objective of this project was to investigate the effect of a commonly used wetting agent, Primer 604, on turf quality and leaching of two fungicides from two contrasting rootzones. The preliminary conclusions are as follows: 1. The wetting agent (WA) improved turf quality of straight sand rootzones during the warm and dry summer. Rootzone containing compost were not affected by WA. 2. WA lead to more water retention in the thatch layer and thus a tendency to more fungi during the rainy fall season. Again, the effect was mostly expressed on straight sand rootzones. 3. Water droplet intiltration tests showed that straight sand rootzones were strongly hydrophobic, even at 3-5 cm depth, i.e. under the thatch layer. Compost-amended rootzones were less hydrophobic, and only in the thatch layer. 4. WA reduced the spatial variation in soil water content, notably in the 4-15 cm layer on straight sand plots. This suggest that water percolation was more uniform after use of WA. 5. Fungicide leaching did not occur from Green Mix rootzones, even for azoxystobin + propicionazole used at high "American" rates. 6. Use of WA significantly reduced leaching of the fungicides iprodione, azoxystrobin and propiconazole from straight sand rootzones.
Forfattere
Erik Joner Deborah OughtonSammendrag
Public concern for the environmental consequences of spreading manufactured nanoparticles is growing, but research on these aspects is only starting to gain momentum, and very little is know about how manufactured nanoparticles interact with environmental matrices like soils, sediments and natural waters. Some progress has been made on toxicity and ecotoxicity, and it is now accepted that some manufactured nanoparticles may have harmful effects on certain organisms. A crucial aspect in toxicity is however the mode and extent exposure, and apart from toxicity dose-response relationships in clean in vitro systems, practically nothing is known on uptake, metabolism, bioaccumulation and excretion. One of the reasons for this is the lack of suitable detection methods for manufactured nanoparticles when these are added to complex media like soil. We have developed a tool for tracing and quantifying mineral-based nanoparticles that has recently permitted the demonstration of their uptake and retention as compared to excretion in vivo. With this method, we have demonstrated that Co3O4 nanoparticles are ingested and absorbed in earthworms, and that these nanoparticles are to a large extent absorbed and retained within their body. The implications of these findings for ecotoxicity and ecological risk assessment studies, and the extension of this methodology for examination of environmental fate and toxicity of other manufactured nanoparticles, will be discussed.
Sammendrag
Kontroll av vegetabiler for restmengder av plantevernmidler har tradisjonelt vært utført ved hjelp av GC med selektive detektorer som NPD og ECD. En slik instrumentering krever en manuell tolkning av kromatogrammer fra de to detektorene samt at overskridelser av grenseverdier og påvisning av ulovlig bruk må verifiseres med analyse på GC-MS. Tolkningsdelen krever lang erfaring og mange måneders opplæring av personell. I tillegg er den svært tidkrevende (0,5-1 time pr. prøve). Tolkningen av kromatogrammene er såpass komplisert og operatøravhengig at mulighetene for å utgi falske negative prøvesvar alltid er til stede. Full Scan GC-MS analyse kombinert med Deconvolution Reporting Software (DRS) fra Agilent Technologies erstatter den manuelle tolkningen med automatisk søk i to databaser med massespektra. DRS programvaren er en applikasjon som kombinerer resultatene fra MS-chemstation, AMDIS (Automatic Mass Spectral Deconvolution and Identification Software) og NIST (National Institute of Standards and Tecnology) databasesøk. Den automatiske tolkningen tar kun 1-2 minutter pr. prøve og resultatene skrives ut på en rapport. Vår erfaring viser at GC-MS-DRS sparer tid, gir sikrere identifikasjon og avslører flere pesticider i prøvene. I tillegg har det vært mulig å senke bestemmelsesgrensen for en rekke pesticider.
Forfattere
Inger Sundheim Fløistad Hans Martin HanslinSammendrag
The Christmas tree seedlings typically appear with initial slow growth during the first 2-3 years. In the next couple of years the trees grow well, and then during the final 2-3 years before harvest the growth frequently is too vigorous. This growth rhythm often requires laborious growth regulation by mechanical or chemical methods. A dense concentration of branches on the lower part of the tree tends to allocate a lot of resources to the tree base, which grows wide and heavy. Such trees are costly to cut and transport and difficult to sell. Therefore, the growers want transplants with rapid growth after planting. To satisfy their demand there is a need for better plant materials than what are available today. More knowledge is needed about the relation between seedling quality, their physiological status and the plants response to different planting dates. In the year 2007 a new project "Seedling qualities and establishment routines for a rapid growth start of Abies nordmanniana and Abies lasiocarpa for Christmas tree production" was established in Norway to improve our knowledge of establishment of Christmas trees. Financial support is given by the Norwegian Research Council, "Skogtiltaksfondet" and "Forskningsfondet for Norsk Pyntegrønt Forsøksring".