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.
2012
Forfattere
Randi Seljåsen Per Lea Torfinn Torp Hugh Riley Erling Berentsen Mette Thomsen Gunnar BengtssonSammendrag
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Sammendrag
Various oils can be used to lower the equilibrium moisture content and increase the service life of Scots pine wood products. The aim of this study was to investigate effects of the lateral wood zone on the brown rot resistance of untreated and linseed oil-impregnated Scots pine wood in a laboratory test (EN 113). Significant differences were found in the mean mass losses of treated and untreated specimens taken from three lateral heartwood zones, but not between specimens taken from sapwood. The treatment had no significant effect on sapwood, although it seems to have some positive effect on the durability of heartwood, apparently due to interactive effects with the high extractives contents of heartwood.
Sammendrag
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Forfattere
Lone Ross Gobakken Geir Isak VestølSammendrag
Wooden claddings are common in faades in Norway, and Norway spruce (Picea abies) is the most frequently used species. The cladding is a major part of the facade, and it has visual requirements that may define the aesthetic service life. The visual changes that occur during weathering can be colour changes, abrasion or wear, blistering, flaking, and even cracks in the wood or coating, but more often growth of mould and blue stain fungi are the main challenge.A field test with synchronous monitoring of relative humidity, air temperature, material temperature and wood moisture content in Norway spruce claddings has been established in southern Norway as part of the ClimateLife project. Visual evaluation of blue stain and mould growth according to EN 927-3 was performed, and evaluation data after 10 months exposure is presented.The objectives were to study the effect of 1) environment, 2) cardinal direction and 3) colour of the cladding on growth of blue stain and mould fungi, and further study the variation in relative humidity, air temperature in front of a surface and the material temperature due to change in 1) environment, 2) cardinal direction and 3) colour of the cladding.After 10 months exposure, the red coating system had lowest mould ratings and the uncoated claddings had the highest. Claddings facing south tend to have higher mould ratings than those facing north. No difference was found between shaded and open environment.The relative humidity was higher in front of the claddings exposed in a shaded environment compared to an open environment, and in an open environment the relative humidity was lower against south than north. The temperature in front of the red coloured claddings was highest. Except for the red-coated claddings, the air temperature was higher than the material temperature.
Sammendrag
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Forfattere
Michel VerheulSammendrag
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Sammendrag
Cover crops are included in cropping systems in order to achieve various ecological benefits. In stockless organic cereal systems in Scandinavia, nitrogen is commonly supplied by undersowing a legume shortly after sowing. Retarding the growth of annual weeds is considered an additional benefit of using cover crops. However, studies on the influence of undersown cover crops on the growth of perennial weeds are lacking. In this paper we present data from a four- year field experiment on the growth of Cirsium arvense (L.) Scop., Sonchus arvensis L. and Elymus repens (L.) Gould., in cereals with and without undersown red clover (Trifolium pratense L.), combined with contrasting stubble treatments after harvest. Clover did not significantly reduce the growth of any of the weed species. Regression analyses showed, however, that the growth of C. arvense and S. arvensis increased with increasing clover biomass at low densities of clover, whereas at higher densities it decreased with increasing biomass of clover. Amongst the stubble treatments, shallow ploughing followed by harrowing gave the best control of all weed species. The effect was most pronounced on E. repens, and least on S. arvensis, for whichneither the number nor the weed biomass were significantly different from the untreated control. Rotary tilling gave a similar effect, but again less pronounced on S. arvensis. Mowing suppressed E. repens to some degree, tended to suppress S. arvensis (n.s.) but had no effect on C. arvense. Thegrowth and survival of seed-propagated plants of the same species were studied in a one-year field experiment and in a greenhouse experiment, the latter only including the species S. arvensis andC. arvense. The use of a cover crop reduced the number of leaves per plant in S. arvensis both in the field and in the greenhouse. The same effect was found for C. arvense, but only in the greenhouse experiment. In the latter, above-ground biomass of the cover crop explained 67 % of the variation intotal biomass of S. arvensis and 47 % of that for C. arvense. From a practical point of view, the study has shown that undersown red clover has only marginal effects on perennial weeds, in contrast to various stubble treatments which influence strongly on weed growth. In general, soil tillagesuppresses perennial weeds best, but mowing may be a more environmentally friendly alternative for some weed species, such as. E. repens.
Sammendrag
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Sammendrag
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Sammendrag
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