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
Næringsstofmangel hos nordmannsgran kan ofte erkendes på nålefarven. Dette videnblad giver eksempler på nålesymptomer ved mangel på kvælstof, magnesium, kalium og mangan.
Forfattere
May-Guri Saethre Trond HofsvangSammendrag
Timed catches of Cydia pomonella (L.) males in sex pheromone traps were used to investigate the influence of twilight and climatic parameters on the flight activity of the moths at different latitudes. Traps were operated from 15 May until 31 July at several locations between 59ºN and 60ºN in south-eastern Norway, and at Sogndal (61ºN) in western Norway, during 1997-2000. Time and duration of twilights were calculated from May-August for each trap-location, and compared with the activity of C. pomonella. Flight response appeared to be determined by the daily photoperiod, corresponding to time of sunset at the different latitudes involved in the study. This response began about two hours before sunset, and declined around 23:00 and 24:00 hours in the evening, in western and eastern Norway, respectively. Main flight activity in both eastern and western Norway was recorded when temperatures were in the range 10-20 ºC, the relative humidity was above 50 %, and at wind speeds below three m/s at the time of capture. In Norway, light conditions are suitable for C. pomonella flight activity all night long during the entire lifetime of the adult moths. It is concluded that temperature is the limiting factor for flight at high latitudes.
Sammendrag
In a survey in one conventional and four organic apple orchards in southeast Norway insect pathogenic fungi and parasitoids as natural enemies of green apple aphid (Aphis pomi) and rosy apple aphid (Dysaphis plantaginea) were studied weekly throughout the summer 2002 and 2003. Four species of insect pathogenic fungi in the order Entomophthorales were observed to infect both aphid species. These were Entomophthora planchoniana, Neozygites fresenii, Erynia neoaphidis and Conidiobolus obscurus. The highest fungal infection level in A. pomi was 39,6 % and 33,3 % in D. plantaginea. Neozygites fresenii was the fungal species being the most prevalent. This fungus also seemed to cause an epizootic in A. pomi and to decrease the aphid population in one organic location during the summer 2002. Parasitoids were a more important mortality factor in A. pomi than in D. plantaginea, and the highest parasitization recorded in A. pomi was 30 %. Four species of primary parasitoids hatched from A. pomi: Binodoxys angelicae, Lipolexis gracilis, Praon sp. and Ephedrus sp. Hyperparasitoids that hatched from A. pomi were Dendrocerus carpenteri, Alloxysta pleuralis, Phaenoglyphis villosa and Asaphes suspensus. Only one individual of D. plantaginea was parasitized and this parasitoid was Ephedrus persicae. Both fungi and parasitoids were abundant early in the season. The fungi were found from late June and throughout the season in some locations in 2002. Resting spores of N. fresenii were found in A. pomi in July. The parasitization showed two tops, one early in season (June/July) and one late in season July/August. Fungal infections were more prevalent than parasitoids in D. plantaginea. Fungi and parasitoids were equally important in A. pomi.
Forfattere
Arvid Steen Turid Strøm Sissel Hansen Bal Ram Singh Aksel Bernhoft Espen GovasmarkSammendrag
Herbage selenium (Se) concentration is generally low in Norway. It is unknown, if feeding practises on Norwegian organic farms fulfil the dietary need of Se and vitamin E to sheep and dairy cattle. Therefore, we analysed Se in soil and herbage, and Se and vitamin E in animal blood in the indoor feeding season at 14 organic dairy and 14 organic sheep farms. The herbage Se concentration was low. Approximately 50 and 35 % of all samples in the first and second cut, respectively, had Se concentrations below the detection limit of 0.01 mg/kg dry matter (DM). The median (10th, 90th percentile) Se concentrations were
Forfattere
F. Suliman H.K. French L.E. Haugen B. Kløve P. JenssenSammendrag
Horizontal subsurface "ow constructed wetlands have proven their ef"ciency in treating wastewater and removing the pollutants of concern. Treatment ef"ciency depends on the wastewater residence time, which is a function of the hydraulic loading and the physical conditions of the constructed "lter system, which can be described with effective parameters such as: hydraulic conductivity, porosity, dispersivity etc. Because spatial variability is often scale dependent, these effective parameters may be affected by the scale of the system being studied. In this paper the results of tracer experiments in constructed "lters using saturated horizontal "ow at three scales (small and medium lab scales and full-scale system) using the same "lter media is reported. Light-weight aggregate ("lter media termed Filtralite-PTM) was used at all scales. Increasing the scale was associated with increasing dispersivity, meanwhile hydraulic conductivity experienced dramatic reduction and variation by increasing the examined scale. Observed changes in the hydraulic parameters indicate that heterogeneity at different scales should be taken into account when the performance of LWA "lters are evaluated from small-scale experiments. KeywordsHeterogeneity; hydraulic parameters; horizontal subsurface "ow constructed wetlands.
Forfattere
Astrid Johansen Mats HøglindSammendrag
Delrapport til UMB, med fokus på ressursgrunnlaget for mjølkeproduksjon på beite og faktorar ved beitet og bruken av beitet som verkar inn på mjølkeyting, mjølkekvalitet og økonomi. Det er peika på framtidig forskingsbehov.
Forfattere
Astrid Johansen Tor LunnanSammendrag
Sluttrapport til oppdragsgjevar Gilde Norsk Kjøtt BA.
Forfattere
Astrid Johansen Tor LunnanSammendrag
Stråfattig italiensk raigras sådd i blanding med korn kan gi velgjæra surfôr med høg næringsverdi dersom det vert hausta til rett tid under gunstige haustingsforhold. Samtidig gir gjenveksten av raigraset næringsrike, vekstkraftige beite utover hausten.
Forfattere
Astrid JohansenSammendrag
Artikkel med råd om stell og gjennomføring av beitedrift i mjølkeproduksjonen.
Forfattere
Astrid JohansenSammendrag
Artikkelen omhandlar korleis beitegrøda og gjennomføringa av beitinga påverkar beiteopptaket, med særleg vekt på framtidige utfordrinar og mulegheiter for å produsere lammekjøt basert på innmarksbeite.