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.
2017
Sammendrag
Aims: Evaluate biological nitrogen fixation (BNF) and its contribution to total N yield in different grass-clover mixtures under a boreal coastal climate and assess how winter conditions affect the survival of clover and its capability to fix nitrogen (N). Methods: Grass-clover mixtures sown with 0, 15 and 30% red and white clover were subjected to two N rates and three levels of tractor trafficking over four years. BNF was estimated by N-difference for each of the two harvests per year, whereas the first harvest was used to estimate the fraction of N derived from the atmosphere (NdfA) and its transfer to grasses by 15N natural abundance. Results: Biological N fixation, mainly by red clover, contributed substantially to total N yield, which was up to 75% greater in grass-clover mixtures than in pure grass stands in the second production year. However, the number of red clover plants and associated BNF decreased dramatically in the third and fourth production year, with N fertilization rate having a more detrimental effect than soil trafficking. Conversely, the amount of biologically fixed N transferred to grass, increased with time, evidencing that some of the biologically fixed N is retained in the system. In the first harvests, NdfA values were generally between 80 and 100%, irrespective of preceding winter conditions. Conclusions: BNF in high latitude grass-clover mixtures can be substantial but is limited by the poor survival of red clover. Variable winter conditions had no measurable effect on winter survival nor on the sward’s capacity to fix nitrogen in spring.
Forfattere
Tatjana Kince Ruta Galoburda Dace Klava Lolita Tomsone Santa Senhofa Evita Straumite Garry Kerch Arta Kronberga Ievina Sturite Daiga Kunkulberga Anita BlijaSammendrag
The aim of the study was to investigate changes of physical, microbiological, and sensory properties of muesli with germinated fakes during storage. Germinated fakes were made from conventionally grown grains: hullless barley, hull-less oat, rye, wheat, and triticale in various proportions. Breakfast cereals samples were packaged in Doypack (stand up pouches) made from Pap50g/Alu7/ Pe60 (Pap/Alu/PE) and stand up pouches Fibrecote® HB MG 40/60 (PE/EvOH/Pap) and stored for 6 months at temperature t=35±2°C and relative air humidity φ=55±3%, to provide accelerated shelf-life testing. The main quality parameters such as total plate count, yeasts and mould, water activity, moisture content, water absorption and sensory properties—taste, aroma, consistency, and appearance were analysed using the standard methods. The results of the present experiments demonstrate that the best quality of dried breakfast cereals after storage in terms of sensory quality, microbiological stability, moisture migration, and water absorption were achieved in the Fibrecote® HB MG 40/60 pouches. This study revealed that breakfast cereals made from rye, triticale germinated triticale, germinated hull-less oat, germinated hull-less barley fakes; as well breakfast cereals made from triticale, oat, germinated wheat, germinated triticale, and germinated hull-less barley fakes packaged in Fibrecote® HB MG 40/60 can be stored for 12 months at temperature 23±2°C; but breakfast cereals made from wheat, rye, triticale, germinated hull-less oat, germinated hull-less barley, germinated rye fakes and package in same packaging material can be stored for 10 months at temperature 23±2°C.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Ievina SturiteSammendrag
Det er ikke registrert sammendrag
Forfattere
Ievina SturiteSammendrag
Det er ikke registrert sammendrag
Forfattere
Ievina SturiteSammendrag
Det er ikke registrert sammendrag
Forfattere
Evita Straumite Ruta Galoburda Lolita Tomsone Zanda Kruma Ilze Gramatiņa Arta Kronberga Ievina SturiteSammendrag
Det er ikke registrert sammendrag
Sammendrag
Red clover (Trifolium pratense L.) is normally a short-lived perennial with no vegetative propagation and the number of plants in the field declines rapidly. In organic farming, the amount of clover in the field is decisive for the N2 fixation and yield, the protein content and quality of the forage produced. In Nordland County (66.27°N), there is a farm with some red clover plants in more than 15 years old grassland. In the presented study we examined grassland botanical content and attempted to recognise age of red clover plants. Our hypotheses was 1) that extensive grassland management promotes self-seeding of red clover 2) self-seeding maintaining a desired content of red clover over time. In addition, we tested two harvesting regimes of the first cut for seed maturation and seed quality at two locations in Norway. Red clover plants in old swards showed very high age and a branched root system. Only very few seedlings were found in old sward suggesting that self-seeding was insignificant. Experiments with leaving the grassland after the first cut for seed production of clover failed due to poor seed maturation. Surface seeding of red clover in pure grass plots gave good results, especially with early spring seeding.
Sammendrag
Insulation is an essential component of nest structure that helps provide incubation requirements for birds. Many species of waterfowl breed in high latitudes where rapid heat loss can necessitate a high energetic input from parents and use down feathers to line their nests. Common eider Somateria mollissima nest down has exceptional insulating properties but the microstructural mechanisms behind the feather properties have not been thoroughly examined. Here, we hypothesized that insulating properties of nest down are correlated to down feather (plumule) microstructure. We tested the thermal efficiency (fill power) and cohesion of plumules from nests of two Icelandic colonies of wild common eiders and compared them to properties of plumules of wild greylag goose Anser anser. We then used electron microscopy to examine the morphological basis of feather insulating properties. We found that greylag goose down has higher fill power (i.e. traps more air) but much lower cohesion (i.e. less prone to stick together) compared to common eider down. ese differences were related to interspecific variation in feather microstructure. Down cohesion increased with the number of barbule microstructures (prongs) that create strong points of contact among feathers. Eider down feathers also had longer barbules than greylag goose down feathers, likely increasing their air-trapping capacity. Feather properties of these two species might reflect the demands of their contrasting evolutionary history. In greylag goose, a temperate, terrestrial species, plumule microstructure may optimize heat trapping. In common eiders, a diving duck that nests in arctic and subarctic waters, plumule structure may have evolved to maximize cohesion over thermal insulation, which would both reduce buoyancy during their foraging dives and enable nest down to withstand strong arctic winds.
Sammendrag
Denne rapporten oppsummerer resultatene fra er treårig forskningsprosjekt vedrørende den unike ærfuglduna. Dunprøver fra 19 kolonier i fire ulike land ble renset på en standardisert måte og ulike parametere ble målt og testet som fill power, sammenhengskraft og resiliens. Det ble dokumentert variasjon i ulike parametere både mellom kolonier og mellom individer. Dette er den største og mest dyptgående studien av ærfugldun som har blitt utført. This report sums up the result from a three-year lasting study regarding the unique eider down. Eider down from 19 colonies was collected and we measured various parameters such as fill power,cohesion and resilience. Overall, this is the largest and most in-depth study of eider down ever performed.