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.
2002
Forfattere
Dag RøenSammendrag
Reglar for økologisk landbruksproduksjon set sterke avgrensingar på kva innsatsmiddel som kan brukast i økologisk epledyrking. Ved val av sortar må vi då legge enda større vekt på motstandsevne mot skadegjerarar enn i integrert dyrking. Særleg er det viktig å velge sortar som er sterke mot skurv. Vi tilrår sortane "Aroma" og "Discovery" som hovudsortar for økologisk epledyrking. "Nanna", "Eir", "Idunn" og "Katinka" vert tilrådd som prøvesortar, og framlegg til kombinasjonar med desse som pollensortar til hovudsortane vert skissert.
Sammendrag
Summary: In Norway there exist a very limited number of studies on soil variability within soil map units. The main purpose of this study has been to provide information on and describe the variability in soil hydraulic properties and soil water content of a silty clay loam of South-eastern Norway. Measurements of soil hydraulic properties were carried out along a 50 meter transect during summer 2000. The measurements included: 1) laboratory saturated hydraulic conductivity (Kls), measured on 100 cm3 cores, 2) infiltration rate (q(h)), measured with tension infiltrometer at matric potentials h = -15, -6 and -3 cm, and 3) soil surface water content, measured in the top 5 cm of the soil with a TDR probe. Field saturated and near saturated hydraulic conductivity (Kfs and Kf(h)) were estimated from the infiltration rates. Variability in hydraulic conductivity was moderate to high along the transect, with coefficients of variation (CV) ranging from 79 for K(-15) to 224 % for K(-6). The sample distribution was approximately lognormal. Kls varied from 1.0 to 341 cm/h, with an arithmetic mean (AM) of 46 cm/h. Kfs was less than Kls, ranging from 0.27 to 63 cm/h, with AM = 13 cm/h. Spatial correlation of all variables was examined by computing variograms. Kls showed some degree of spatial correlation, with a effective ranges of approximately 7 meters. The nugget variance was rather high compared to the sill, indicating a large random component related to small-scale variability and measurement errors. Field hydraulic conductivity generally showed no clear sign of spatial correlation, except for Kf(-6)6,15, which had a range of 9.6 m. Soil water content was measured at six dates during the growing season. The spatial patterns varied from time to time. Where spatial correlation existed, effective ranges varied from 4.3 to 7.4 meters. As with Kls, the variation appeared to be dominated by a random component. From these results it was concluded that 1) at this scale of investigation, hydraulic conductivity exhibits a large degree of random variation related to soil heterogeneity and sample volume, 2) the most appropriate approach for modelling water flow and solute transport using these data would be to use the probability density function of the attributes, and 3) spatial trends and scale should be considered when planning the experimental design to assure that the sampling scheme encompasses a complete picture of the processes under investigation.
Forfattere
Reidun Pommeresche Reidun PommerescheSammendrag
This study focusses on the spider fauna in two organically managed leys in different stages of a crop rotation and in one permanent pasture, all on the Tingvoll Farm in northwestern Norway. Spiders were collected by means of pitfall traps; the sampling period lasted from 28 April to 23 June 2000. Altogether 2415 specimens, representing 48 species, were found. A DCA-analysis shows differences in the spider populations found in the leys compared with the pasture, but less difference between the young and older ley. However, the number of species and the dominance pattern of the spider populations differ between the young and older ley. A total of 16 species were found in the young ley, 26 species in the older ley and 34 species in the pasture. Bathyphantes gracilis, Erigone atra, Oedothorax fuscus and Savignia frontata were the most abundant species in the leys, with Pardosa amentata and Silometopus elegans the most abundant in the pasture. Collinsia inerrans was represented by 83 specimens in the leys. This species is previously recorded only twice in Norway, and has been placed on the national Red List proposal.
Forfattere
Peder Gjerdrum H. Säll H.M. StorøSammendrag
Any evident grain deviation will reduce strength and increase warp in sawn timber. To describe the magnitude and variance of grain angle in Norway spruce, specimens from 1046 Norwegian sawlogs and 380 logs from Sweden and Finland were examined. For individual specimens, grain angle outside the innermost zone closest to the pith might be expressed by a simple linear function of radial distance from the pith. The intercept and inclination of this function are close to bivariate normally distributed with mean values (SD) of 2.7 deg. (1.9) and -0.039 deg/mm(0.037), respectively. Inclination is less negative for wider annual rings (r = 0.3), and intercept and inclination are negatively correlated (r = -0.4). The constant rate of change indicates inherited property rather than influence of any dynamic, external stimulus. No predictor for grain angle pattern was found. The linear model leads to simplifications both when observing the grain angle in the forestry, and in calculations of strength properties and distortion in the timber industry.
Forfattere
Thomas HartnikSammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
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Det er ikke registrert sammendrag
Forfattere
Lars Sandved Dalen Carl Gunnar Fossdal R. Bhalerao John Beck Jensen Teemu H. TeeriSammendrag
Trees cover over one-third of the world\"s land area and carry out about two-thirds of global photosynthesis. Coniferous forests cover 1.2 billion hectares of Alaska, Canada, Scandinavia, and Russia, and comprise one-fourth of the world\"s boreal and temperate forests. More than 50% of Scandinavia\"s land area consists of forests, mostly coniferous. Information about the molecular responses in trees to biotic and abiotic factors is therefore of great importance - both scientifically and practically. Generation of expressed sequence tags (ESTs) is an important part of genome research. Randomly selected cDNA clones are partially sequenced, and the ESTs reflect the level and complexity of gene expression in the sampled tissue. In order to find interesting gene products and to study gene expression in the most common and economically important conifer in the Nordic countries, we have started an EST-project on Norway spruce. So far we have sequenced ~3500 cDNA clones based on mRNA isolated from needles and cell cultures. Here, we present the frequency of the different ESTs, their putative function and their functional classification. We aim at sequencing another 20,000-30,000 cDNA-clones from wood-forming tissues and from seedlings treated with drought, low temperatures, pathogen infection, etc. The long-term goal is to develop a non-redundant and annotated collection of Norway spruce clones to be used in combination with microarray analysis
Sammendrag
Artikkelen gir en presentasjon av siste års resultater med prøving av ulike midler mot overvintringssopp i høstkorn. Sammendrag for flere år blir også presentert. Problemer med overvintringssopp i høstkorn er ikke en årviss foreteelse i områdene for høstkorndyrking, heller ikke i de indre strøk. I år med soppangrep kan imidlertid skadene bli store. En behandling med et soppmiddel vil kunne hindre store årsvariasjoner, og meravlingen betaler i de fleste tilfelle for behandlingen. Sikkerheten i høstkorndyrkingen blir følgelig større. Behandling er viktigst i de indre deler av Østlandet, på store planter og med korn (hvete, bygg eller rug) som forgrøde. I områder med mer ustabilt snødekke bør kornplantenes størrelse ved innvintring, forgrøde og mengden av spillkorn, ugras og halm i overflata ha betydning for avgjørelsen om behandling. Sportak er det eneste tillatte midlet til behandling mot overvintringssopp. Ingen av strobilurinene er godkjent for bruk om høsten.
Sammendrag
Det er ikke registrert sammendrag