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.
2005
Sammendrag
Resultater viser at høsteregimet influerer på kvitkløverens innhold av N om høsten, tapet av N fra stoloner gjennom vinteren, og akkumulasjon av N i nye blad om våren. Resultatene antyder også at N tapt fra kvitkløveren gjennom vinteren kan være svært mobilt.
2003
Forfattere
Marianne UlebergSammendrag
Et stort problem for bruk av kvitkløver i eng og beitemark i dag er sen vårvekst. Det medfører at det blir lite kvitkløver i første slåtten og at plantene lettere utkonkurreres av gressene. Ved Nordnorsk kompetansesenter på Holt har et større feltforsøk blitt utført for å undersøke effekt av ulike driftsmåter på vinteroverlevelse og vårvekst hos kvitkløver. De foreløpige resultatene antyder at beite og slått ikke virker negativt på vårveksten til kvitkløver
Sammendrag
White clover (Trifolium repens L.) is a perennial legume forming nitrogen fixing symbiosis with the soil living bacteria Rhizobium leguminosarum bv. trifolii. The species is the most important pasture legume in temperate zones, despite the fact that it grows poorly at low temperatures. The poor growth at low temperatures currently restricts utilization of the species as a natural nitrogen source in northern areas. Both nitrogen fixation and growth of white clover is limited in spring, probably due to low temperatures. This drawback is particularly pronounced under northern climatic conditions where temperatures are low during most of the growing season. Better understanding of the growth and nitrogen dynamics of white clover at low temperatures is vital for successful management of white clover/grass pastures and optimisation of biological nitrogen fixation, especially at northern latitudes. In a research project with field experiments conducted under different climatic conditions, we are studying winter survival, spring growth and nitrogen dynamics of white clover in relation to its physiological condition. We are especially focusing on below ground biomass and the functioning and longevity of roots and nodules. The physiological condition of the plants is manipulated by the use of different defoliation regimes during the growing season. The field experiments are situated at two locations (Apelsvoll at 61°N, and Tromsø, 690N). Preliminary results will be presented.
2002
Sammendrag
In a recently started research project with field experiments conducted under different climatic conditions, winter survival, spring growth and nitrogen dynamics of white clover are studied in relation to its physiological condition. Belowground biomass and the functioning and longevity of roots and nodules are especially focused. The physiological condition of the plants is manipulated by the use of different defoliation regimes during the growing season. The field experiments are situated at two locations; at Apelsvoll at 61°N, and in Tromsø, 69°N. The results show that the defoliation regimes affected the strategy of DM allocation in the white clover plants. The more frequent defoliation regime lead to increased allocation of photosynthates to leaves at the expense of roots and stolons. The defoliation regimes thus created a gradient in physiological condition of the plants