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.
2005
Forfattere
Manfred Bölter Nathalie Soethe Rainer Horn Christian UhligSammendrag
Seasonal development of soil microbial activity and bacterial biomass in sub-arctic regions was investigated to determine the impacts of biotic and abiotic factors, such as organic matter content, temperature and moisture. The study was performed during spring thaw from three cultivated meadows and two non-cultivated forest sites near Alta, in northern Norway. Samples from all five sites showed increasing respiration rates directly after spring thaw with soil respiration activity best related to soil organic matter content. However, distributions of bacterial biomass showed fewer similarities to these two parameters. This could be explained by variations of litter exploitation through the biomass. Microbial activity started immediately after the thaw while root growth had a longer time lag. An influence of root development on soil microbes was proposed for sites where microorganisms and roots had a tight relationship caused by a more intensive root structure. Also a reduction of microbial activity due to soil compaction in the samples from a wheel track could not be observed under laboratory conditions. New methodological approaches of different staining for live and dead organisms were applied in order to follow changes within the microbial community. Under laboratory conditions freeze and thaw cycles showed a damaging influence on parts of the soil bacteria. Additionally, different patterns for active vs. non-active bacteria were noticeable after freeze-thaw cycles.
Forfattere
Line Rosef Helge BonesmoSammendrag
The growth potential of four semi-natural grasslands with rotational grazing was studied during four growing seasons. A crop growth model was used to quantify growth potential and to separate the influence of weather variables from factors related to the plant stand. The investigation revealed a high variability in dry matter (DM) production among years during the study period due to weather. There was also found to be a clear seasonal variation. The general shape of the DM production curve, with a rapid spring growth (the maximum relative growth rate (Rs) = 0.16 g g-1 day-1), a midsummer depression (Rs = 0.06 g g-1 day-1), and a second peak of growth in late summer (Rs = 0.09 g g-1 day-1), was the same for all years and for all fields. The model underestimated production when cover of herbs was low in spring and overestimated production when cover of herbs was high in spring. The seasonal and among years variation in DM production entailed a parallel large variability in the numbers of grazing animals (from 11 to 43 heifers ha-1) the area could sustain.
Sammendrag
The content of selected plant constituents was measured in cherry tomatoes (Lycopersicon esculentum Mill. cv Jennita) during conventional Norwegian tomato production in a greenhouse from May until October 2004. Samples were collected according to standard production procedure with orange-yellow coloured fruits at weight in the range of 12.4 -19.3 g and size in the range of 28.9-33.0 mm (diameter). The content of selected compounds based on 100 g FW were found to vary in the following range during the season: 7.38-28.38 mg chalconaringenin, 0.32-0.92 mg rutin, 0.24-1.06 mg chlorogenic acid, 5.60-20.02 mg ascorbic acid, 1.60-5.54 mg lycopene and 0.37-0.55 mg b-carotene. Only minute amounts of naringenin together with kaempferol 3-rutinoside and caffeic acid, which previously have been reported from tomatoes, were detected. The content of chalconaringenin to rutin, and that of lycopene to b-carotene showed a strong correlation during the season (p < 0.001). The content of total phenolics and methanol soluble antioxidants also showed a correlation (p < 0.001), and were found in the range 14.6 - 32.6 mg GAE/100 g FW and 445 - 737 mmol FeII/100 g FW, respectively. Seasonal variation in the level of plant constituents is shown to be related to photon flux density and fertilization level.
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Forfattere
Trond MæhlumSammendrag
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Forfattere
Dag-Ragnar BlystadSammendrag
Kort orientering om sharkavirus - spredning, symptomer og skade
Forfattere
Dag-Ragnar BlystadSammendrag
Sharkavirus (Plum pox virus) er en karanteneskadegjører som angriper plomme og noen andre Prunus-arter. Angrep kan medføre nedsatt fruktkvalitet og betydelig avlingsreduksjon.
Sammendrag
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