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.
2008
Forfattere
Aslaug Helgadottir Petter Marum Sigridur Dalmannsdottir Kristin Daugstad Thordis Anna Kristjansdottir Tor LunnanSammendrag
Background and aims: White clover (Trifolium repens) is an important component of sustainable livestock systems around the world. Its exploitation for agriculture in the northern, marginal areas, is, however, currently limited by the lack of cultivars that combine persistence and high production potential. The aims are to investigate whether it is feasible to create breeding material of white clover for these areas by combining winter hardiness of northerly populations with good yielding ability of more southerly cultivars. Methods: A total of 166 crosses of 14 different parental combinations between winter-hardy, low-yielding populations of northern origin and high-yielding commercial cultivars of more southerly origin were tested under field conditions in Iceland and Norway and the parental combinations were compared in Norway. Spaced plants were transplanted into a smooth meadow grass (Poa pratensis) sward. Dry matter yield was estimated for 2 years after planting in Norway and morphological characters associated with yielding capacity were measured at both sites. Key results: The results showed that southerly cultivars had larger leaves and higher yielding potential than northern types but suffered more winter damage. Significant variation was found between full-sib families within the different parental combinations for all morphological characteristics measured in all three trials. However, it was difficult to detect any consistens morphological patterns between progeny groups across trial sites. No significant correlations were found between leaflet area and survival. Conclusions: The present study has confirmed that it should be possible to simultaneously select for good winter survival and larger leaves and, hence, higher yielding ability under marginal conditions.
Forfattere
Rimvydas Vasaitis Bo Långström Halvor Solheim Ylva Persson Katarina Ihrmark Jan StenlidSammendrag
Ips typographus is economically most important insect pest of mature spruce in Eurasia. Normally, it prefers to reproduce in dead and/or dying trees, but following large-scale storm disturbances, its outbreaks kill waste areas of living stands. One factor triggering such epidemics is a surplus of broken and uprooted trees with non-existent, or weak, defence....
Sammendrag
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Sammendrag
In Norway exterior wood structures have traditionally nearly exclusively been made of treated and untreated Picea abies and Pinus sylvestris. In recent years there has been a tendency that other tree species, like various domestic hardwoods and imported species have been used in exterior above ground applications, often unfinished. For several wood species, especially hardwoods, information regarding the durability in use class 3 is lacking. The main objective of this paper is to evaluate natural durability of Norwegian wood species for above ground applications comparing two non-standard above ground tests with the European standard tests for soil contact (EN 252) and lab performance against basidiomycetes (EN 113). The European standard tests EN 113 and EN 252 gave quite similar results, and they also corresponded well with the natural durability classification in EN 350-2. The two non-standard above ground tests differed to some extend from EN 113, EN 252 and EN 350-2. The results indicate that natural durability classification for one single wood species can change depending on use class. However, the field trials need a longer period of time before a final classification can be performed. Four species not included in EN 350-2 were classified in this study: Juniperus communis (1), Salix caprea (5), Sorbus aucuparia (5) and Populus tremula (5).
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Peter Simon Erik JonerSammendrag
In this paper, we made an attempt to assess the conceivable interactions of insoluble, persistent nanoparticles with food matrix and living systems following from their physicochemical properties and to outline the analytical methods for the nanoparticles determination in food matrix. It is reasoned that adsorption of species and agglomeration and ageing of nanoparticles are phenomena originating in the relaxation of surface free energy. Further it has been deduced that nanoscale materials have a unique aility to interact with proteins and other biopolymers. The deductions also underline the catalytic activity of nanoparticles, primarily in oxodative reactions which may lead to the formation of reactive oxygen species and to the oxidative stress. The ability of nanoparticles to act as nuclei or germs in the induced heterogeneous crystallization is also considered.
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
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Forfattere
Randi Berland Frøseth Sissel Hansen Anne Kjersti BakkenSammendrag
Heilårs grøngjødsel er ei viktig nitrogenkjelde til økologisk korn i eit omlaup utan tilgang på husdyrgjødsel. Dagens praksis med fleire gongars slått og grønmasse som vert liggjanse på stubben for å rotne medfører stor risiko for nitrogentap. Målet med forsøket var å undersøkje i kva grad N i liggjande grønmasse bidreg til byggavlinga året etter. Resultata viser 10 % lågare eller ingen forskjell i byggavling etter heilårs grøngjodsel der grønmassen vart fjerna frå feltet samanlikna med der han vart liggjande etter kvar slått. Meiravlinga på 0,4 kg N per daa tilsvarte berre 3 % av N i overjordisk plantemasse av grøngjodsla. Kor stor del av N fra grønmassen som gjekk tapt ved utvasking eller gasstap og kor stor del som vart bygd inn i organisk materiale, og dermed tilgjengeleg for seinare kulturar, vart ikkje målt.
Forfattere
Randi Berland Frøseth Sissel Hansen Anne Kjersti BakkenSammendrag
Heilårs grøngjødsel er ei viktig nitrogenkjelde til økologisk korn i eit omlaup utan tilgang på husdyrgjødsel. Dagens praksis med fleire gongars slått og grønmasse som vert liggjanse på stubben for å rotne medfører stor risiko for nitrogentap. Målet med forsøket var å undersøkje i kva grad N i liggjande grønmasse bidreg til byggavlinga året etter. Resultata viser 10 % lågare eller ingen forskjell i byggavling etter heilårs grøngjodsel der grønmassen vart fjerna frå feltet samanlikna med der han vart liggjande etter kvar slått. Meiravlinga på 0,4 kg N per daa tilsvarte berre 3 % av N i overjordisk plantemasse av grøngjodsla. Kor stor del av N fra grønmassen som gjekk tapt ved utvasking eller gasstap og kor stor del som vart bygd inn i organisk materiale, og dermed tilgjengeleg for seinare kulturar, vart ikkje målt.