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.
2006
Sammendrag
A system for winter greenhouse production of strawberries was developed in Norway. Plants of the June-bearing cultivar `Korona" were artificially induced to flower with short-day (SD) treatments. Plants were induced to flower three times: in July, in September and in December, and were harvested from November to June. Three-week old strawberry plants exposed to fourteen 12-hour SD cycles in May, were compared to non-treated plants (control) and large, cold-stored tray-plants. Photoperiod preconditioned plants produced significantly more branch crowns than control plants, but less than cold-stored tray-plants. Preconditioned plants produced more fruits than control plants, but the difference was not significant. Cold stored tray-plants had the highest total yield. Large multiple-crown, cold-stored tray-plants are of variable quality and expensive in Norway. Photoperiodic preconditioning is potentially useful for increasing strawberry productivity and therefore the profitability of a winter greenhouse production system.
Forfattere
Scott Laidlaw Lars Nesheim John Frame Juan PineiroSammendrag
Climatic zones in Europe range from semi-arid in the Mediterranean basin to polar and so intensity of seasonality in forage production differs widely, influenced mainly by temperature and soil moisture. Management systems which overcome seasonal limitations vary. Forage may be conserved at times of excess supply, whether of grass or crops, for feeding stock in times of undersupply, principally as silage and hay. Seasonal forage growth curves can be manipulated by the use of fertilizer (mainly nitrogen), by irrigation, by selection of appropriate species and varieties, including development of secondary grasses and legumes, and by grazing management. Alternative forages or feeds such as maize, cereals, brassicas, a range of crop byproducts, and fodder trees and shrubs (in some regions) are valuable complements to grassland forage. Management systems including adjustment of stocking rates to reflect more closely grass growth and forage supply and their efficient integration, or changing stock reproduction cycles contribute to overcoming seasonality. The additional constraint of minimizing adverse environmental impact in any strategy to overcome seasonality is acknowledged and some possible means of utilizing the feed resources to minimize nitrogen and phosphorus losses are considered. It is concluded that while decision support systems are useful in aiding farmers to make decisions to deal with seasonality problems, more information is required on the true costs of producing grassland forage and complementary feed alternatives to ensure options can be intelligently chosen.
Forfattere
Hallvard Jensen Per-Arne Amundsen J. Malcolm Elliott Thomas Bøhn Paul Eric Aspholm Paul Eric AspholmSammendrag
Prey consumption rates of piscivorous brown trout, Salmo trutta, were studied in the Pasvik watercourse, which forms the border between Norway and Russia. Estimates of food consumption in the field were similar to or slightly less than maximum values from a bioenergetic model. The piscivore diet consisted mainly of vendace, Coregonus albula, with a smaller number of whitefish, C. lavaretus. Individual brown trout had an estimated mean daily intake of approximately 1·5 vendace and 0·4 whitefish, and a rapid annual growth increment of 7-8 cm year-1. The total population of brown trout >25 cm was estimated as 8445 individuals (0·6 individuals ha-1), giving an annual consumption of 1553880 (±405360 S.E.) vendace and 439140 (±287130 S.E.) whitefish for the whole watercourse. The rapid growth in summer of brown trout >25 cm indicated a high prey consumption rate.
Forfattere
R. Lahmar S. de Tourdonner P. Barz R-A Düring M. Frielinghaus R. Kolli J. Kubat Jan Netland V. Medvedev D. PicardSammendrag
In Europe, Conservation agriculture (CA) is less adopted than in the other world adopting regions and, reduced tillage is more used than no-tillage. Use of cover crop is not common. It is currently less researched than it was before the 1990s. One of the main features of CA is the reduction of the production costs which acts as a powerful driving force for the dissemination of CA technologies. In Europe, conversion from conventional agriculture to CA leads to a minor change in yields: ± 10% depending on the countries; and, this is not decisive for farmers as far as CA meets their main expectation: i.e. reduction in costs of fuel, machinery and labour saving. The adoption process responds to a step-by-step strategy and, large sized farms are the main adopters. The increase in competitiveness at the global and at European level; the general trend of the increase of CA coverage world-wide and the current level of fuel costs together with the trend of the enlargement of the farm size in Europe will probably contribute to the adoption of CA in Europe. The process is likely already ongoing in some European countries; it has to be sustained.
Forfattere
Tor Håkon SivertsenSammendrag
Norwegian Institute for Agricultural and Environmental Research" is the owner of a network of meteorological stations, established in 1987. 45 of the stations are measuring global radiation, hourly values. These time series are to be used as one of the input parameters for modelling UV-radiation. Also several other meteorological parameters of relevance for modelling UV-radiation are measured in this station network and discussed below. A discussion on quality of these data contains general considerations on the concept of quality, considerations on the methods for making measurements at the specific series from a few sites as well as specific quality considerations on several other available time series of meteorological parameters, like the albedo, precipitation, relative humidity of the air, temperature of the air etc. from the sites. Elements describing the sites are mentioned, like information on the horizon, the geographical coordinates etc. The availability of independent time series of measurements of ozone, cloudiness, precipitation, content of aerosol and vertical distributions of humidity to be used in models are also discussed. Modelling UV-radiation at the ground is defined as a complex problem of data integration using data from different sources. The main part of this paper contains discussion complex data integration.
Forfattere
Tor Håkon SivertsenSammendrag
`Norwegian Institute for Agricultural and Environmental Research" is the owner of a network of meteorological stations, established in 1987. 45 of the stations are measuring global radiation, hourly values. These time series are to be used as one of the input parameters for modelling UV-radiation. Also several other meteorological parameters of relevance for modelling UV-radiation are measured in this station network and discussed below. A discussion on quality of these data contains general considerations on the concept of quality, considerations on the methods for making measurements at the specific series from a few sites as well as specific quality considerations on several other available time series of meteorological parameters, like the albedo, precipitation, relative humidity of the air, temperature of the air etc. from the sites. Elements describing the sites are mentioned, like information on the horizon, the geographical coordinates etc. The availability of independent time series of measurements of ozone, cloudiness, precipitation, content of aerosol and vertical distributions of humidity to be used in models are also discussed. Modelling UV-radiation at the ground is defined as a complex problem of data integration using data from different sources. The main part of this contribution contains discussion complex data integration.
Forfattere
Åshild Ergon Cheng Fang Øyvind Jørgensen Trygve S. Aamlid Odd Arne RognliSammendrag
Kartleggingsfamilien "BF 14/16 x HF2/7" i engsvingel ble karakterisert for følgende frøavlsegenskaper: Krav til primærinduksjon (uker ved 6°C og 8 timer daglengde), tidlighet (skytedato), andel av skudd som danne frøstengel etter 12 ukers primærinduksjon, og antall frøstengler hos ikke-induserte planter i såingsåret (feltforsøk). "Quantitative trait loci" (QTLer) ble identifisert og sammenliknet med QTLer og gener som styrer blomsgterinduksjon i andre grasarter, herunder kornartene. En region på kromosom 1F hadde betydning for tidlighet og andel skudd som dannet frøstengel. Primærinduksjonskravet var styrt av gener på kromosom 4F, særlig i en proksimal region som korresponderer med tidlighetsgenet QTL eps6L.2 i bygg og tidlighet i flerårig raigras. Et område korresponderende til venaliseringsgenet VRN1 ble også ble påvist på kromosom 4F. Den proksimale enden av kromosom 5F hadde stor betydning for tidlighet og andel skudd som dannet frøstengel, mens kromosom 6F var med å bestemme antall frøstengler i feltforsøket. En region på kromosom 7F hadde betydning for antall frøstengler hos ikke-induserte planter i såingsåret, og dette samsvarer med regioner i flerårig raigras, bygg og ris med samme gensekvens som i modellplanten A. thaliana CO.
Forfattere
Kim Johansen Marianne TomtumSammendrag
I overvåkingsprogrammet for rester av plantevernmidler i vegetabilske næringsmidler er det tatt ut og analysert totalt 547 prøver i andre tertial 2006. Det er analysert 467 rutineprøver av frisk frukt/bær, grønnsaker, krydderurter og poteter, 19 prøver av barnemat, 40 prøver av matkorn, 20 prøver for kartlegging av vegetabilske matvarer fra Asia og èn prøver av appelsinjuice (EU koordinert program). Det har i perioden vært to tilfeller av funn i økologiske produkter, henholdsvis sitron fra Spania og epler fra Argentina. I eplene fra Argentina ble det funnet så mye av skadedyrmiddelet dimetoat at det ble vurdert til å kunne representere helserisiko. Verdiene overskred i tillegg gjeldende grenseverdi for konvensjonelt dyrkete epler. I tillegg er det i én prøve av bønner med belg fra Thailand påvist samme middel (dimetoat) i mengder som har blitt vurdert til å kunne representerer helserisiko. Resultatene fra overvåkingsprogrammet viser for øvrig at 62,3 % av de undersøkte stikkprøvene av vanlig frisk frukt, bær, grønnsaker og poteter er uten påvisbare rester av plantevernmidler. I 18 varepartier er det påvist rester over gjeldende grenseverdi. For matkorn er 62,5 % uten påvisbare plantevernmiddelrester. I ett parti norsk rug av sorten Picasso er det påvist rester over gjeldende grenseverdi av stråforkortningsmiddelet klormekvat. I kartleggings¬prosjektet "Vegetabilske produkter fra Asia" er kun 15 % av de 20 prøvene uten rester av plantevernmidler, mens 50 % av prøvene inneholder rester over gjeldende grenseverdi.
Sammendrag
Environment Synthesis) family of crop models predicts cereal growth, development, and yield. CERES simulates nitrogen (N) as a yield"limiting macronutrient. Because N leaching is an economic and environmental concern, this study evaluated if CERES can be used to predict N leaching under different N management scenarios: background leaching in unfertilized corn (Zea mays L.), alfalfa (Medicago sativa L.) residue mineralization, and till versus no"till management. Data were collected during a 7"yr field experiment on tillage practices in a maize"alfalfa"maize succession. Sensitivity analyses were performed for decomposition rates of the different residue pools and the relative proportions of carbohydrate, cellulose, and lignin in the residues. During the last 5 yr, under corn, CERES accurately simulated nitrate leaching from the no"till lysimeters. Nitrate leaching was underestimated in the tillage treatments, possibly because CERES does not simulate tillage. The model is not very sensitive to the decomposition rates and to the composition of the residues
Forfattere
Lars Tørres Havstad Trygve S. AamlidSammendrag
Split nitrogen (N) application to seed crops of timothy (Phleum pratense L.) was evaluated in twenty field trials, eleven in the South-Norwegian cultivar "Grindstad" (origin 59oN) and nine in the North-Norwegian cultivar "Vega" (origin 67oN) in Southeast (58-61ºN) and Central (63-64ºN) Norway during 1998-2000. Three N rates (25, 50 or 75 kg N ha-1) at the start of growth were combined with four N rates (0, 25, 50 or 75 kg N ha-1) at the start of tiller elongation (Z 31). On average for all trials, the highest seed yield was obtained when a total rate of 75 kg N ha-1 was split into a main application of 50 kg N ha-1 at the start of growth and a supplemental application of 25 kg N ha-1 at Z 31. In both cultivars, the optimal N rate at Z 31 was uncorrelated with soil mineral N (NO3 + NH4) in early spring and only weakly correlated (r2=0.16-0.17, P%=2-5) with the N concentration of aboveground plant material at Z 31. In "Grindstad", a better correlation (r2=0.46, P%