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
Forfattere
Arnstein Øvrum Kyrre RickertsenSammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Due to sewage sludge application on soils, terrestrial ecosystems are very likely to be exposed to silver nanoparticles (AgNPs) and it is thus important to understand the behavior of Ag NPs once in contact with soil components. The aim of this work was to compare the behavior of silver under three forms, silver nitrate, citrate stabilized AgNPs (C-ANPs) and uncoated AgNPs (P-AgNPs), in two soils with contrasting organic matter content, and over time. The physical and chemical properties of the studied soils as well as the nanoparticles size, shape, crystallographic structure and specific surface area were characterized. Soil samples were spiked with silver nitrate, C-AgNPs or P-AgNPs, and let for ageing 2 hours, 2 days, 5 weeks or 10 weeks before they were submitted to sequential extraction. The ionic silver solution and the two AgNPs types were radiolabeled so that we could detect and quantify silver by gamma spectrometry by measuring the 110mAg tracer in the different sequential extraction fractions. We thereby obtained for each silver form, soil type and time point a distribution of silver in the different fractions. Silver was generally more mobile in the mineral soil, although the fractionation patterns were very different for the three silver types in both cases. Over 20% of the total C-AgNPs concentration were water soluble in both soils (<5% for AgNO3 and P-AgNPs) the first two days after spiking, but the fraction decreased to trace levels thereafter. This was compensated by an increase in the reducible fraction. Regarding P-AgNPs, 80% were not extractable at all, but contrary to AgNO3 and C-AgNPs, the water soluble and ion exchangeable fractions did not decrease over time in the mineral soil, and even increased in the organic soil.
Forfattere
Atle HaugeSammendrag
Det er ikke registrert sammendrag
Forfattere
Tor J. JohansenSammendrag
Dormancy in a potato tuber prevents sprout growth even under optimal sprouting conditions and is the first stage in the physiological ageing process. The intensity and duration of this phase differs between genotypes (cultivars) and may also be affected by environmental conditions both during tuber bulking and early storage. The current study aimed at finding how simulated high latitude growth conditions influence dormancy and the physiological age of tubers to be used as seed potatoes. In a controlled climate at natural light conditions, tubers grown at a low temperature (9°C) had 2-3 weeks shorter dormancy than tubers grown at higher temperatures (15 and 21°C). In tubers grown at artificial light conditions, day-lengths (12, 18 or 24 h) did not affect dormancy significantly. A post-harvest treatment with a low temperature (one month at 4°C and subsequently 18°C) reduced dormancy by 2-3 weeks in tubers from the highest growth temperatures (15 and 21°C) in comparison with constant 18°C post-harvest. After the lowest growth temperature (9°C) the duration of dormancy was not affected by post-harvest temperature treatments. Physiological age was determined by sprouting characteristics after winter storage. At this stage the sprouting capacity was highest in tubers originating from the lowest and the highest growth temperatures. Further, the number of sprouts per tuber was higher in tubers grown at 9°C than at 15 or 21°C. These results were not correlated with duration of dormancy after the various treatments, suggesting that temperatures may affect dormancy and physiological ageing independently. The present results show that dormancy may be shortened by low grow temperatures, and similarly by low post-harvest temperatures at higher growth temperatures.
Forfattere
Tor J. JohansenSammendrag
Det er ikke registrert sammendrag
Forfattere
Cecilie Marie Mejdell Grete Helen Meisfjord Jørgensen Therese Rehn Linda J Keeling Kjersti Elisabeth Fremstad Knut Egil BøeSammendrag
Det er ikke registrert sammendrag
Forfattere
Cecilie Marie Mejdell Grete Helen Meisfjord Jørgensen Therese Rehn Linda J Keeling Knut Egil BøeSammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Redaktører
Eva Narten HøbergSammendrag
Det er ikke registrert sammendrag