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
Ved bruk av metoden som gjev avling annakvart år, blir bringebærfelta delt i to klart skilde fasar; nemleg den vegetative fasen der skota veks opp, dannar blomsterknoppar og overvintrar. Det følgjande året er kjem den generative fasen då avlinga blir hausta. I England blir bringebæra dyrka i plasttunnel. Ved annakvart års bering treng ein berre å dekke det feltet som gjev avling. Dersom feltet som blir hausta annakvart år, gjev meir enn halve avlinga i forhold til tradisjonell dyrking, vil dei spare pengar på plastdekking. I dette eksempelet fekk dei dobbel avling i feltet der dei la opp til annakvartårsbering. Dei skriv då at kostnadane til plasttunnelar kan halverast.
Forfattere
Anita SønstebySammendrag
Vindruedyrkermiljøet i Noge er lite, men stadig økende. Nye og bedre sorter tilpasset kjølig klima er nå kommet på markedet. I dag finnes noen få sorter som vi med sikkerhet vet kan lykkes i vårt kjølige klima.
Forfattere
Hugh RileySammendrag
Alternative tillage systems that avoid autumn ploughing are being used in Norway, primarily to reduce nutrient transport to waterways, but also to maintain soil quality and reduce costs. Yield results are presented for six long-term trials, four on loam soil and two on heavy clay. Straw residues have been retained in all cases, and weed problems have been avoided by frequent spraying. The trials have shown considerable variation between years in yield responses to tillage, probably as a result of weather variations, but no long-term trends have been observed. The trials have shown that average yields without ploughing but with autumn harrowing are usually at least 95% of those obtained with ploughing. With spring harrowing only, the long-term yield is likely to be in the region of 90-95%, whilst direct drilling may give somewhat greater yield reductions.
Forfattere
Olav Martin Synnes Anne Kjersti Bakken Sissel HansenSammendrag
A field trial, a pot experiment and a survey in organically farmed leys were undertaken to investigate whether the N-fixation in red clover pastures in Norway was limited by a low supply of Co and/or Mo. Fertilization with Mo did not cause any higher production nor Nfixation, whereas the N-yield both from established clover leys and red clover grown in pots increased slightly after application of Co to many of the investigated soils. In the organically farmed leys there was a significant and positive correlation between the Co-content and the N-content of the red clover. As many of the investigated clover-soil systems were of those previously known to be very low in Co and Mo, and the gain in N-yield obtained by extra Cosupply was marginal, it is not likely that deficiency of these trace elements is a problem that deserves any great concern in legume based forage production systems in Norway.
Forfattere
Astrid Johansen Anne Kjersti Bakken Olav Martin SynnesSammendrag
It has been investigated whether green fodder crops and dicotyledonous weeds may contribute to more balanced diets for ruminants, according to Co, Cu and Mo, than perennial grasses do. Vicia faba was found useful for diets otherwise low in Co or with a high Cu:Mo-ratio. To increase the Cu:Mo-ratio Lolium multiflorum and Raphanus sativus were the most appropriate species.
Forfattere
Tor Arvid Breland Anne Kjersti Bakken Trond K Haraldsen Trygve S. Aamlid Tore E SveistrupSammendrag
Temporal changes in the scores of selected soil fertility indices were studied over six years in three different cases of organic crop rotation located in southern, eastern and central Norway (Bakken et al. in press). The cropping history and the initial scores of fertility indices prior to conversion to organic cropping differed between the sites. Crop yields, regarded as an overall, integrating fertility indicator, were in all rotations highly variable with few consistent temporal trends following the first year after conversion. On the site in eastern Norway, where conversion followed several years of all-arable crop rotations, earthworm number and biomass and soil physical properties improved, whereas the system was seemingly degrading with regard to P and K trade balances and contents in soil. On the other two sites, the picture was less clear. On the southern site, which had a relatively fertile soil before conversion, the contents of soil organic matter and K decreased during the six-year period, but the scores of other fertility indices showed no trends. On the site in central Norway, there were positive trends for earthworm-related indices such as worm biomass and tubular biopores and negative trends for soil porosity. The results, especially those from the eastern site, illustrate the general difficulty in concluding about overall fertility or sustainability when partial indicators show divergent trends. Consequently, the study gave no unambiguous support to the initial working hypothesis that organic farming increases inherent overall soil fertility, but rather showed that the effect varied among indicators and depended on status of the cases at conversion. It is concluded that indicators are probably better used as tools to learn about and improve system components than as absolute measures of sustainability.
Forfattere
Øyvind Nordli Finn Måge Frans-Emil Wielgolaski Stein Harald Hjeltnes Anne Kjersti Bakken Oddvar Skre Endre SkaarSammendrag
The analyses are based on phenological observations carried out at international phenological gardens (IPG) at Fana (western Norway) and Kvithamar (Trøndelag), also at the Norwegian University of Life Sciences (Ås, south-eastern Norway) and the research station Njøs (Sogn, western Norway). The longest series are from Njøs (1927) and Ås (1947), whereas no series at the IPGs is older than 1964. For the three southernmost sites (Ås, Fana, and Njøs) all trends are negative, i.e. there has been a change towards earlier occurrences of the phenophases in spring. For the northernmost site (Kvithamar) also positive trends are seen. Four species are cultivated at Fana as well as at Kvithamar. For these species the trend lines are steeper at Fana than at Kvithamar. For the longest series (1927 - 2005) the trend is only -0.4 day/decade but insignificant (p > 0.05). This amounts only to about 3 days earlier occurrence (apple at Njøs) within this period of 79 years. The trend at Ås (1947 - 2005) is also insignificant, although it amounts to about -1 day/decade or about 6 days earlier occurrence within the 59 year period.
Forfattere
Sissel Hansen Anne Kjersti Bakken Turid Strøm Espen Govasmark Håvard Steinshamn Espen Govasmark Sissel Hansen Turid Strøm Håvard SteinshamnSammendrag
There is generally low atmospheric sulphur (S) deposition in northern Scandinavia. Because of this, the herbage S content on 28 organic farms was monitored in order to discover eventually shortage in the S-supply for plants or ruminants in organic livestock production. The S content and the protein content were generally low. In spite of this, the yields were surprisingly good in many locations, and S fertilisation improved yields, biological nitrogen fixation and the protein content of red clover only when the S supply was very low. In a pot trial, increasing S application did not increase the S content of red clover above a certain level. That level depended on the growing conditions. Instead of an increase in the shoots with increasing S supply, there was an accumulation of S in the roots.
Forfattere
Espen Govasmark Arvid Steen Turid Strøm Sissel Hansen Anne Kjersti BakkenSammendrag
Based on a survey on Norwegian organic farms observations it was concluded that today"s feeding practice for sheep and dairy cattle herds was sufficient regarding Cu and Co, but Se should be supplemented to all animals and vitamin E should be supplemented to animal diets consisting mainly of hay.
Forfattere
Bård Pedersen Helge Bonesmo Anne Kjersti BakkenSammendrag
The paper gives examples of how data acquired by image analysis of digital photographs can be processed and interpreted by descriptive, spatial statistics for analyses of two-dimensional patterns in grass-clover swards. We use local quadrat variance methods to identify scales and intensities of patterns in the sward and wavelet analyses to identify individual clover patches and study their dynamics.