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.
2004
Forfattere
Otto SjelmoSammendrag
Det er ikke registrert sammendrag
Forfattere
Ivar Mysterud Lars Olav Eik Leif Jarle AsheimSammendrag
The paper discusses the economics of substituting some ranging sheep with cashmere goats, employing a Linear Programming model. Studies of grazing pattern reveal that threes and bushes constitute about 50 percent of feed intake of browsing goats, compared to 10 percent for sheep. Goats are thus more efficient than sheep in reducing pasture encroachment. Under Norwegian climatic conditions encroachment of bushes and trees will not affect the probability of wild fires, however, maintaining open landscapes is considered an important goal for the development of the rural countryside. Comprehensive alteration from sheep to cashmere goats with eight months old kids averaging 11 kg slaughter weight, is unprofitable, assuming equal labour input of goats and sheep. However, goats are smaller and require less feed, thus the labour input of goats may be lower. Due to the low fibre yield cashmere goats are not as profitable as sheep, even excluding subsidies for wool. The fibre yield could be improved by breeding or by feeding the kids until 20 months (19 kg), making goats as profitable as sheep. The current agricultural support system treats sheep and goats equal. However, if Norway’s position in the ongoing WTO-negotiations to allow for extra payment forpreserving the cultural landscape (multifunctional agriculture) gains sufficient support, extra compensation for browsers should become interesting to the government in implementing the policy.
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Using Singular System Analysis (SSA), we extract a collection of significant long-term components (with dominant periods of at least 3 years) for a large number of river runoff records.At first glance, these long-term modes are a distinct feature of this variable, not contained in precipitation and temperature, and not easily correlated to commonly known long-term indices (NAO, SOI, NHT, SUN, etc.). However, low-pass filtered versions of these time series exhibit strikingly similar behavior, like common maxima, within a region (such as Southern Germany), pointing to a common origin.Although not an unequivocal example for synchronization, we quantify the degree of synchronization as a function of the regional extent of the data and propose a mechanism, stochastic resonance, discussed in climate dynamics, which is able to produce this collective behavior despite the lack of deterministic drivers. We also comment on air pressure-induced teleconnections between the different large scale oscillations in the climate system.
Forfattere
Maja Cuvardic Steinar Tveitnes Tore Krogstad Peder LombnæsSammendrag
Det er ikke registrert sammendrag
Forfattere
Dag RøenSammendrag
Rubinstep" og "Rubinola" har synt seg lovande i førstprøving ved Bioforsk Njøs. Vi har no fleire nye sortar frå dei tsjekkiske foredlingsprogramma under utprøving.
Forfattere
Håkon BorchSammendrag
Det er ikke registrert sammendrag
Forfattere
Juliana Irina Spies PerminowSammendrag
Lys ringråte har forekommet i Norge i lengre tid, den første påvisningen ble gjort i 1964. Siden 1999 har det foregått en lansdekkende kartlegging av forekomsten, initiert av Landbrukstilsynet (nå Mattilsynet). Det ble funnet mest lys ringråte i de nordlige fylkene og i sortene Mandel, Troll og Pimpernel. Bekjempelsesstrategien omfatter desinfeksjon av lager og redskap på de infiserte gårdene, destruksjon av smittet plantemateriale, to års karantene på potetarealet og utskifting av settemateriale. Etterkontroll 3-4 år etter at tiltakene ble satt igang har vist en betydelig reduksjon av infiserte gårder. Mørk ringråte har aldri blitt påvist her i landet. Siden 1998 har all settepotet, som blir innlevert til statskontroll hvert år, blitt testet for mørk ringråte. I årene som fulgte har også prøver av matpotet fra risikoområder, prøver av vaskevann og flytende avfall i potetindustribedrifter, samt vannprøver fra vassdrag som mottar utslipp fra disse bedriftene, blitt testet. Det ble ikke påvist mørk ringråte i noen av disse prøvene, men det er god grunn til fortsatt å være på vakt mot sykdommen pga. av muligheten for introduksjon av smitte ved usikker import.
Forfattere
Arild SlettenSammendrag
Løkhvitråte er en karanteneskadegjører på ulike løkvekster. Den kan gi betydelig avlingstap.
Forfattere
Tor Håkon SivertsenSammendrag
In a small area of fruit production in southern Norway are placed four automated meteorological stations owned by The Norwegian Crop Research Institute. The measurements made at the stations are hourly recordings of precipitation, air temperature, leaf wetness and relative humidity of the air, plus some additional measurements of wind velocity, temperature of the soil and global radiation at two of the stations. The area has a relatively smooth topography with hills and no mountains. The highest point is located about 500 m above the sea level, and the lowest point is 16 m above sea level at the shores of the lake Norsjø, and most of the commercial orchards in the area are situated between 20 and 150 m above the sea level. The remote sensing research group at The Norwegian Meteorological Institute is providing hourly radar measurements of precipitation, from two different weather radars for this area (Gjertsen and Dahl, 2001). These measurements are collected each hour and stored in a systematic way in a database. One of the intentions of this project is to combine/compare measurements of meteorological parameters at the four automated stations with the weather radar measurements of precipitation. The precipitation data used is documented according to a system developed by The Norwegian Crop Research Institute. The representativeness of the different measurements of meteorological parameters is discussed and connected to a prediction model of apple scab infection, called modified Mills table (MacHardy and Gadoury, 1989, and Stensvand et. al, 1997) containing information on minimum air temperature and leaf wetness duration in specified periods. The original Mills table was published in 1944 ( Mills, 1944). A system for extrapolation, interpolation and combination of the relevant information mentioned is developed to get figures of temperature and leaf wetness duration to be put into the extended Mills table at all sites of this region. The usefulness of the system is to be tested and hopefully made partly operational in the growing season to come. The relevant information is communicated to the local private extension service. The intention of combining development, testing and operational use of a system is an important element of this project. References: Mills, W.D., 1944, Efficient use of sulfur dust and sprays during rain to control apple scab, Cornell Extension Bulletin, 630, 4 pp. MacHardy, W.E. & Gadoury, D.M., 1989: A revision of Mills" criteria for predicting apple scab infection periods, Phytopathology 76: 985-990 Stensvand, A, Gadoury, D.M., Amundsen, T., Semb, L., and Seem, R.C., 1997, Ascospore release and infection of apple leaves by conidia and ascospores of Ventura inaequalis at low temperatures, Phyopathology 87 : 1046-1053 Gjertsen, U. and Dahl, I., 2001, Development of a gauge adjustment method for correcting of radar precipitation estimates, Research report No. 128/2001, The Norwegian Meteorological Institute, Oslo, Norway