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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.

2018

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Sammendrag

Lengre vekstsesong og høyere temperaturer om høsten gir spørsmål om de anbefalte høstetidspunktene for eng fortsatt er gyldige og om ettervekst etter hovedslåtter bør høstes eller kan få stå. Vi har undersøkt effekt av tidspunkt for høsting og antall slåtter på mengde og kvalitet av etterveksten, og konsekvenser for overvintring og avling neste år av å enten la etterveksten stå, eller høste den med jevne mellomrom utover høsten mot vekstavslutning. I forsøk i eng dominert av timotei (Phleum pratense L.) på Holt (Tromsø), Løken (Øystre Slidre), samt flere steder i Troms og Finnmark har vi undersøkt ettervekst etter tidlig og sein 2. slått. På Kvithamar (Stjørdal) og Fureneset (Fjaler) har vi målt gjenvekst etter to eller tre slåtter i timoteidominert eng, samt gjenvekst etter 3. slått i flerårig raigras (Lolium perenne L.). Etterveksten er generelt lav sjøl om høsttemperaturene er blitt høyere. Dette skyldes antakelig svært lav lysinnstråling i høstmånedene, noe som forsterkes dess lengre nord en kommer. Fôrkvaliteten er god. Det hadde ingen negative konsekvenser å la etterveksten stå. Høsting av ettervekst bidro til mindre timotei det påfølgende året, spesielt i nord. I raigras hadde høsting av ettervekst negativ effekt både på avling i 1. slått og total avling det påfølgende året.

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Sammendrag

Climate change and its effects on grassland productivity vary across Europe. The Mediterranean and Nordic regions represent the opposite ends of a gradient of changes in temperature and precipitation patterns, with increasingly warmer and wetter winters in the north and increasingly warmer and drier summers in the south. Warming and elevated concentration of atmospheric CO2 may boost forage production in the Nordic region. Production in many Mediterranean areas is likely to become even more challenged by drought in the future, but elevated CO2 can to some extent alleviate drought limitation on photosynthesis and growth. In both regions, climate change will affect forage quality and lead to modifications of the annual productivity cycles, with an extended growing season in the Nordic region and a shift towards winter in the Mediterranean region. This will require adaptations in defoliation and fertilization strategies. The identity of species and mixtures with optimal performance is likely to shift somewhat in response to altered climate and management systems. It is argued that breeding of grassland species should aim to (i) improve plant strategies to cope with relevant abiotic stresses and (ii) optimize growth and phenology to new seasonal variation, and that plant diversity at all levels is a good adaptation strategy.

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Sammendrag

We investigated climatic trends in two contrasting locations in Europe at a regional level and at two specific sites, and we analysed how these trends are associated with the dry matter yield (DMY) of agriculturally improved grasslands. Trends of different meteorological variables were evaluated for Wielkopolska province, central Poland (1985-2014) and Troms county, northern Norway (1989-2015), as well as for two research stations located in these regions. Significant trends of increased mean air temperatures annually, and in April, June, July, August and November were identified both at the regional and site levels in Wielkopolska. In addition, growing degree days were increasing in Wielkopolska. In Troms, the common trends for the region and site studied were increase in mean air temperature in May and decrease in January. Grassland DMY was subsequently regressed against those meteorological variables for which significant trends were detected. In the Wielkopolska region, yields were negatively associated with the increase in air temperature in June, August, and the annual air temperature. The last relationship was also detected at the site level. We did not find any significant effects of climate trends on grassland DMY in the Norwegian study site or region.

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Sammendrag

The potential of seaweeds as alternative protein source was investigated in relation to their amino acid (AA) profiles and the ruminal and total tract digestibility of these AAs. Three red (Mastocarpus stellatus, Palmaria palmata, and Porphyra sp.), four brown (Alaria esculenta, Laminaria digitata, Pelvetia canaliculata, and Saccharina latissima), and two green (Cladophora rupestris. and Ulva sp.) seaweed species were used in this study (hereafter, referred to by Genus name only). All seaweeds were collected in Bodø, Northern Norway, during Spring and Autumn in 2014 and 2015, except Ulva, which was only sampled in Autumn of both years, and Saccharina which was not sampled in Spring 2014. All the samples were studied for AA concentration. Six species (Cladophora, Laminaria, Mastocarpus, Palmaria, Porphyra and Ulva) were selected for the more resource demanding in situ study. Species and season interactively affected the content of total AA in crude protein in different seaweeds investigated (P=0.02), with values ranging from 67.2 for Laminaria in Spring to 90.2 gAA/16 g N for Ulva in Autumn. in situ AA degradability was also species specific. The seasonality of total AA in crude protein of different seaweed species mostly did not affect their ruminal degradability, except for alanine, while species and season interactively affected proline’s ruminal degradability. The total tract degradability showed that for Laminaria and Mastocarpus, methionine followed by leucine, isoleucine, histidine and lysine, were protected against rumen degradation. These protections seemed to be acid labile allowing digestion in the lower digestive tract. However, due to high indigestible fractions, these two seaweeds provided low amounts of AA to the intestines. Total tract AA digestibility values were the highest for Porphyra (906 g/kg) followed by Palmaria (843 g/kg) and the green seaweeds. To conclude, Laminaria and Mastocarpus are beneficial sources for bypass protein supply as they contain AA protected against rumen degradation. Based on their amount of AA and their AA degradability, Porphyra, followed by Palmaria and the green seaweeds (Ulva and Cladophora) can be considered as relevant sources of protein for ruminants.