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.
1999
Forfattere
Halvor SolheimSammendrag
Det er ikke registrert sammendrag
Forfattere
M. Lavoie Peder GjerdrumSammendrag
The aim of this study has been to investigate the effects of high temperature drying on the equilibrium moisture content, to verify the presence of hysteresis and to screen the effects of high temperature on timber quality. Further, we wanted to utilise the laboratory kiln at Forestia Sokna in a pilot project, to learn more about the experimental possibilities connected to this equipment. The hypothesis was that the equilibrium moisture content will decrease as the drying temperature increase. Five series of twelve spruce wood samples each were prepared to verify this hypothesis: air-dried (green samples), moist samples for desorption and dry samples for adsorption for the ordinary-progressive (72 C) and for the high temperature kilns (115 C). The tension has been measured to compare the timber quality between ordinary-progressive and high temperature kilns. The conclusion is that there was too much stochastic noise to verify the initial hypothesis. Consequently it was impossible to confirm the presence of hysteresis. There are interesting observations to make in further research on how fast the equilibrium moisture content is reached according to the drying temperature. This experiment has been accomplished using Norway spruce, and further research should include Scots pine or other coniferous species.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Tor J. Johansen S Finch A JukesSammendrag
Etter sprøyting med pyretroider mot voksne gulrotfluer i gulrot, kan middelrester på bladene drepe fluene i opptil 14 dager etter behandling. Dette går fram av en laboratorieundersøkelse ved HRI Wellesbourne i England. Moderne pyretroider bør utprøves som et alternativ til fosformidler på grunn ubetydelig fare for rester i røttene.
Forfattere
B Darvas Arild AndersenSammendrag
Andalin DC-25, NeemAzal-F and RH 5849 2 F hindret ikke voksne hunner av havrebladminerflue fra å foreta næringsstikk eller legge egg. Trigard 75 WP og Fk-dimetoat hadde derimot tilfredstillende virkning.
Forfattere
Leiv MortensenSammendrag
Seedlings of Phleum pratense L. (timothy) and Betula pubenscens Ehrh. (mountain birch) were grown for 37 or 42 days at all combinations of two CO2 concentrations (350 and 700 mmol mol -1), two O3 concentrations (13 and 59 nmol mol -1 in 8 h day -1 ) two day lengths (17 and 24 h DL) and two levels of supplementary lighting (150 and 210 mmol m -2 s -1 photosynthetic photon flux, PPF) in 16 growth chambers placed in a greenhouse.
Forfattere
Kari Anne SølvernesSammendrag
The impact of climate change, i.e. elevated atmospheric CO2 and increased temperature, on a mini forest ecosystem was studied for three years in an open-top chamber experiment at s, Norway. Clones of Norway spruce (Picea abies L. Karst.) and one clone of Silver birch (Betula pendula Roth.) were grown in monolithic lysimeters containing undisturbed profiles of boreal forest soil. Seedlings and clones of Norway spruce were also grown in pots with fertilised peat. The atmospheric CO2 concentration was increased with 50 and 100 % of the present CO2 concentration, i.e. to approximately 500 and 700 mol mol-1 CO2. Ambient CO2 (380 mol mol-1 CO2) in chambers and at outside control plots (chamber control) were also included. There were two replicates of each treatment.The soil temperature was increased by 2 - 3 C. Growth and chemical composition of plants, leachates and soil chemistry were measured. Elevated CO2 caused a limited growth increase in Norway spruce and Silver birch. The CO2 effect was largest when the plants received good nutrient supply. The effect of CO2 on height increment was probably depended on growth pattern. When the plant exhibited free growth the stimulation of top shoot elongation was larger than when the plant exhibited predetermined growth. The benefit of elevated CO2 was also probably larger for Silver birch than for Norway spruce. The chemical composition of the plants were almost unaffected by elevated CO2. Increased soil temperature caused an increased mineralisation. Increased amounts of N and Al were released and leached from the soil. The data obtained from the leachates from the 500 mol mol-1 CO2 birch lysimeters during the two last growth seasons were surprisingly and not expected. In these leachates the pH and the concentrations of Al and TOC were increased in both replicates compare to the other treatment with birch. It was hypothesised this could be caused by increased exudations of organic compounds from Silver birch roots induced by elevated CO2
Forfattere
Svein Solberg Steinar DraglandSammendrag
Kepaløk ble høstet til ulik tid og etter ulike metoder. Den ble tørket ved ulik temperatur og fuktighet. Virkningene på groing og utviklingen av glassaktige og læraktige løkskjell ble registrert, og sammenholdt med innholdet av O2 og CO2 i løken.
Forfattere
Marit JørgensenSammendrag
Mixtures of white clover and smooth meadow-grass and pure stands of grass were treated with 0, 40, 80 or 120 kg N ha-1. Yields were compared between all treatments and the proportion of white clover in the mixtures was determined. N2 fixation was estimated by the N-difference method. The experiment was established in 1996 on a sandy loam in Tromsø (690 39"N), northern Norway, under subarctic conditions. The clover/grass mixtures yielded more than pure stands of grass. N-levels significantly affected the dry matter production of the grass, but much less of the mixtures. As N-levels increased from 0 to 120 kg N ha-1 , the yields of the mixture rose from 4.1 t ha-1 to 5.3 t ha-1 while the yields of the grass in pure stand increased from 1.2 t ha-1 to 4.8 t ha-1. Increasing N-levels caused a decrease of the proportion of white clover in the mixtures. With 0 kg N application, white clover made up 63% of the total dry matter yields, whereas at 120 kg Nha-1 the proportion dropped to 19%. Correspondingly, N-application strongly depressed the yields of fixed N2 from 91 kg N ha-1 when no fertilizer N was added, to 30 kg N ha-1 at the highest N-level.
Forfattere
V. Koski Jouni Partanen H. Hänninen Egbert BeukerSammendrag
Det er ikke registrert sammendrag