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.
2007
Forfattere
Inger Sundheim Fløistad Hans Martin HanslinSammendrag
The Christmas tree seedlings typically appear with initial slow growth during the first 2-3 years. In the next couple of years the trees grow well, and then during the final 2-3 years before harvest the growth frequently is too vigorous. This growth rhythm often requires laborious growth regulation by mechanical or chemical methods. A dense concentration of branches on the lower part of the tree tends to allocate a lot of resources to the tree base, which grows wide and heavy. Such trees are costly to cut and transport and difficult to sell. Therefore, the growers want transplants with rapid growth after planting. To satisfy their demand there is a need for better plant materials than what are available today. More knowledge is needed about the relation between seedling quality, their physiological status and the plants response to different planting dates. In the year 2007 a new project "Seedling qualities and establishment routines for a rapid growth start of Abies nordmanniana and Abies lasiocarpa for Christmas tree production" was established in Norway to improve our knowledge of establishment of Christmas trees. Financial support is given by the Norwegian Research Council, "Skogtiltaksfondet" and "Forskningsfondet for Norsk Pyntegrønt Forsøksring".
Sammendrag
The prediction of infection periods for lettuce downy mildew (Bremia lactucae) is based on the assumption that spores are produced at night and released in the early morning. The divergent light conditions at Nordic latitudes might affect both sporulation and spore release. Therefore, we monitored release of B. lactucae spores in relation to the climatic conditions in lettuce fields to evaluate the performance of existing forecasting models in timing of fungicide applications for management of lettuce downy mildew in Norway. In 2005, epidemics were created at two field locations that had no previous lettuce production, and a total of 59 days of spore trapping permitted the study of spore release under natural conditions. Sporulation events were compared to predicted spore production events in Modell-Analys (MA). At the two locations, 76 % and 74 % of the spores were trapped between 08.00 and 16.00, respectively. Spore concentration icreased with decreasing relative humidity (RH), ofting coinciding with increasing solar radiation and temperature. Spore production events predicted by MA were correct at 66 % of the days. However, when the criteria for spore production were adjusted, 78 % of the days were correctly predicted.
Forfattere
Kinga Adam Anne Kristine Søvik Tore Krogstad Arve HeistadSammendrag
Konstruerte våtmarker og filterbedanlegg brukes verden over for å rense kommunalt avløpsvann. I disse systemene er det viktig å velge et filtermateriale med gode fosfor-bindingsegenskaper, i tillegg til en utforming som fører til en effektiv rensing. Batchforsøk har vært det viktigste verktøyet for å finne maksimal bindingskapasitet for potensielle filtermaterialer. Disse forsøkene har vært utført på mange forskjellige måter, noe som gjør at det er vanskelig å sammenligne resultatene fra de ulike forsøkene. En standard metode for batchforsøk blir derfor foreslått i denne artikkelen, for å lettere kunne sammenligne og rangere fosfor-bindingsegenskapene til ulike filtermaterialer brukt i konstruerte våtmarker og filterbedanlegg. Ekstraksjon av total fosfor (P) fra filtermaterialer tatt fra langvarige laboratorieforsøk og fullskalarenseanlegg viser at langtidsforsøk i laboratoriet gir en bra indikasjon på hvilke prosesser som skjer i fullskalarenseanlegg. Det er imidlertid viktig at slike forsøk har innløpskonsentrasjoner og hydraulisk belastning mest mulig lik det som er brukt i fullskalaanlegg. Endringer av posisjonen til innløp/utløp og valg av filtermateriale er foreslått som måter å bedre renseevnen til disse systemene.
Forfattere
Anne Kristine Søvik Pål Tore MørkvedSammendrag
Artikkelen oppsummerer resultater fra laboratorieforsøk (inkuberingsforsøk og strømningsforsøk) hvor vi har studert rensing av nitrogen i filtermaterialer brukt i konstruerte våtmarker og filterbedanlegg. Inkuberingsforsøkene omfattet ulike filtermaterialer og ulike oksygen- og nitratkonsentrasjoner. Denitrifikasjonsraten og produktforholdet N2O/(N2+N2O) varierte mellom de ulike filtermaterialene. Sand og skjellsand hadde de høyeste denitrifikasjonsratene og de laveste utslippene av N2O. Nytt lettklinkmateriale hadde lav denitrifikasjonsrate grunnet høy pH. Lystgass produsert ved nitrifikasjon økte med økende oksygenkonsentrasjoner. I strømningsforsøket hadde karet med skjellsand best renseevne, mens produksjonen av N2O var høyest i karet med lettklinker. Begge forsøksoppsettene viser at renseevnen for nitrat i lettklinker er betraktelig høyere i eldre renseanlegg enn i nye renseanlegg, mens høy produksjon av N2O ser ut til å vedvare. I filterbed og konstruerte våtmarksanlegg kan en kombinasjon av filtermateriale egnet for denitrifikasjon og filtermateriale med høy P-sorpsjonsevne være en brukbar løsning hvis man ønsker både høy N- og P-fjerning.
Forfattere
Anne-Berit Wold Nina OpstadSammendrag
I et feltforsøk med jordbær plantet på Østlandet, ble tørrgjødsling ved planting i august 2003 sammenliknet med gjødselvatning fra mai 2004. Halve feltet ble gjødslet ved planting og gjødselvatnet med en lav gjødselrate fra våren etter (T1), mens den andre halvparten var ugjødslet ved planting og ble i stedet gjødselvatnet med høg gjødselrate fra våren 2004 (T2). I 2005 fikk begge leddene tilført samme mengde gjødsel. Bærene ble høstet tre ganger per uke i løpet av det første avlingsåret. Bær fra tidlig i sesongen, midt i sesongen og sent i sesongen ble analysert for oppløst tørrstoff, pH, titrerbar syre, farge, vitamin c, antioksidant aktivitet (FRAP) og mineralinnhold. Resultatene ble korrelert med innholdet av mineraler i tørrstoff i blad. T1 ga mørkere og større bær sammenliknet med T2. De andre kvalitetsparametrene og konsentrasjonen av mineraler i bær var ikke signifikant påvirket av gjødslingsstrategiene. Oppløst tørrstoff, pH, titrerbar syre og farge varierte signifikant gjennom sesongen, mens vitamin c og antioksidant kapasiteten (FRAP) ikke var påvirket av gjødsling, bærstørrelse eller tid i sesongen. Resultatene ga en generell oversikt over kvalitetsparametrene i jordbærsorten Korona.
Sammendrag
We evaluated direct and interactive effects of light quality and intensity, temperature and light, diurnal rhythms, and timing of high relative humidity during long day lengths on sporulation of Bremia lactucae, the causal agent of lettuce downy mildew, using inoculated lettuce seedlings and detached cotyledons. Suppression of sporulation by light was strongly dependent upon temperature and there was little suppression at "10°C. The most suppressive waveband was in the range from 400 to 450 nm, although a lesser effect of wavebands from 450 to 500 and 500 to 550 nm could be detected. At 15°C, near the lower threshold for suppression of sporulation by light, a clear diurnal pattern of sporulation was observed independent of light and darkness. This diurnal rhythm potentially could interact with light and temperature to confound the results of controlled environment studies, and may be the controlling factor in timing of sporulation at low temperatures. Forecasting models that currently use sunrise and sunset to delimit periods conducive to sporulation can be adapted to short nights and extended twilight conditions by incorporating the effects reported herein. Additionally, models of sporulation could be adapted to better reflect a decrease or absence of the suppressive effect of light at
Forfattere
Martin Gierus Hendrika Anette van Dorland Anjo Elgersma Michael Kreuzer Ralf Loges Erich M. Poetsch Harm J. Smit Håvard Steinshamn Fridhelm Taube Michael WachendorfSammendrag
Forage legumes are valuable alternatives for mineral N fertilizers in grassland, due to their N fixing capacity and the assumed increase in forage quality of the sward. However, forage quality of binary swards may differ in response to site and legume species. The objective of the present study, carried out within the frame of the COST Action 852, was to identify the influence of legume species growing in contrasting environments on legume proportion, crude protein (CP) and metabolisable energy (ME) contents. At each of the five participating sites the experiment was carried out as a completely randomized block design with three replications. Four legume species were tested: white clover, red clover, alfalfa and birdsfoot trefoil. The first cut was performed in spring after first node detection in grass and repeated 30±3 days afterwards (5-cut system). Legume proportion varied largely from 5% to 79%, with birdsfoot trefoil showing the lowest legume proportion in the swards across sites. Alfalfa had the highest N contents at all sites. Results show that, especially in ME content, legumes are less responsive to variation due to contrasting environments than the companion grass.
Sammendrag
Plant polyphenolics continue to be the focus of attention with regard to their putative impact on human health. An increasing and ageing human population means that the focus on nutrition and nutritional enhancement or optimization of our foodstuffs is paramount. Using raspberry as a model we have shown how modern metabolic profiling approaches can be used to identify the changes in the level of beneficial polyphenolics in fruit breeding segregating populations and how the level of these components are determined by genetic and/or environmental control. Interestingly the Vitamin C content appeared to be significantly influenced by environment (growth conditions) whilst the content of the polyphenols such as cyanidin, pelargonidin and quercetin glycosides appeared to much more tightly regulated suggesting a rigorous genetic control. Preliminary metabolic profiling showed that the fruit polyphenolic profiles divided into two gross groups segregating on the basis of relative levels of cyaniding-3-sophoroside and cyaniding-3-rutinoside, compounds implicated as conferring human health benefits.
Sammendrag
The challenges in providing sufficient food supply and drinking water to a rapidly growing world population are tremendous. Even more so, to meet these challenges without causing unacceptable pressures on the environment and the natural resources with subsequent risks of undermining the potential for feeding future generations. These questions, which basically deal with sustainability, should represent the framework for any development strategy in agriculture, irrespectively of whether the scale is global or local. The need for additional land and access to water represents key constraints in terms of meeting the expected increase in food demand, and would probably require a series of diverse development strategies, depending on both region and site-specific conditions. This presentation discusses different issues linked to the potential conflicts between increased food production in agriculture, and environmental impacts including food safety aspects. Contrasts will be exemplified by the two prevailing trends in agricultural practices; conventional farming practices based on extensive external inputs possibly also with the use of GM crops, and, organic agriculture based on the mineralization of external inputs into the production system. Strategies that may mitigate the pressures on the land and water resources are analysed in terms of quantitative as well as qualitative measures. A development strategy for sustainable agriculture would need to emphasis efficiency in terms of resources utilisation, and integrated approaches in terms of management strategies.
Sammendrag
The challenges in providing sufficient food supply and drinking water to a rapidly growing world population are tremendous. Even more so, to meet these challenges without causing unacceptable pressures on the environment and the natural resources with subsequent risks of undermining the potential for feeding future generations. These questions, which basically deal with sustainability, should represent the framework for any development strategy in agriculture, irrespectively of whether the scale is global or local. The need for additional land and access to water represents key constraints in terms of meeting the expected increase in food demand, and would probably require a series of diverse development strategies, depending on both region and site-specific conditions. This presentation discusses different issues linked to the potential conflicts between increased food production in agriculture, and environmental impacts including food safety aspects. Contrasts will be exemplified by the two prevailing trends in agricultural practices; conventional farming practices based on extensive external inputs possibly also with the use of GM crops, and, organic agriculture based on the mineralization of external inputs into the production system. Strategies that may mitigate the pressures on the land and water resources are analysed in terms of quantitative as well as qualitative measures. A development strategy for sustainable agriculture would need to emphasis efficiency in terms of resources utilisation, and integrated approaches in terms of management strategies.