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
Forfattere
Håkon SundSammendrag
Det er ikke registrert sammendrag
Forfattere
Håkon Sund Norvald RuderaasSammendrag
Det er ikke registrert sammendrag
Sammendrag
Teger er viktige skadedyr i både eple og pære i Norge. I økologisk pæredyrking kan opp mot 40 % av avlinga gå ut grunna tegeskade. Mange av tegeartane som gjer skade i frukt har fleire vertsplanter, og fleire vert rekna som både skade- og nyttedyr. Sprøyting med redusert dose av Lebaycid (fention) har vore tilrådd mot teger i norsk kjernefruktproduksjon. Frå 2005 er dette plantevernmiddelet ikkje lenger lov å nytte i fruktproduksjon i Norge. I dette arbeidet har vi undersøkt effekten av slått av undervegetasjon som eit førebyggjande tiltak mot skade av teger. I tillegg har vi undersøkt ulike kjemiske og biologiske sprøytemiddel sin effekt på teger og skade av desse.a
Forfattere
Seppo NevalainenSammendrag
Det er ikke registrert sammendrag
Forfattere
Tor Håkon SivertsenSammendrag
The concept of classification of meteorological and agro meteorological / biological phenomena is defined as merely giving names to observed phenomena. Examples of certain phenomena are shortly presented, and then a rather unusual statement connected to the concept of classification is presented: Any physical and biological phenomenon contains a totality that includes time, space and consciousness. The concept of parameterization is used in the following manner: We connect measurable / quantitative entities to each phenomenon. The concept of parameter is then discussed as well as the ideas of constructing models containing the macro physics of the air or the micro-physics of the air. A few ideas connected to statistical mechanics are mentioned. And some of the ideas of the `physical laws" used in meteorology are discussed. References: Sivertsen T.H., 2005, Discussing the scientific method and a documentation systems of meteorological and biological parameters, Physics and Chemistry of the Earth Special Issue: Agrometeorology 2003, Vol 30/1-3 pp 35-43 Sivertsen, T.H., 2005, Implementation of a General Documentation System for web-based administration and use of historical series of meteorological and biological data, Physics and Chemistry of the Earth Special Issue: Agrometeorology 2003, Vol 30/1-3 pp 217-222 Sivertsen, T.H., 2005, Discussing scientific methods and the quality of meteorological data, in `Use and Availability of Meteorological Information from Different Sources as Input in Agrometeorological Models", COST ACTIONS 718 `Meteorological Applications for Agriculture", Edited by G. Maracchi, A. Mestre, L. Toulios and B. Gozzini. Sivertsen, T.H, 2005, ", Reflections on the Theme of Classifying, Documenting and Exchanging Meteorological Data", Atmospheric Science Letters, Vol.6 , Issue 3, p 171-175, John Wiley & Son
Forfattere
Tor Håkon SivertsenSammendrag
An interpretation of the scientific principle is presented and shortly discussed, containing the concepts of classification of physical phenomena, parameterization, `physical laws", construction of hypotheses and testing. Then the concept of continuity of the real number system ispresented. The Navier-Stokes equations , the equation of continuity, and the energy equations are interpreted , looking at the concepts of molecular diffusion and convective flow, and the physical content of the `physical laws" of conservation of mass, conservation of momentum and conservation of energy. The construction of the Reynolds equation is discussed by looking at the parameterization in time and space of fluid flow of different temporal and spatial scale. Turbulence is then interpreted as phenomena of fluid dynamics on a smaller scale than the scale of the system for making measurements in each operational situation. The discussion is completed by looking once more at the content of the `physical laws" of of conservation of mass, conservation of momentum and conservation of energy. References: Tennekes, H., & Lumley, J.J., (1972). A first course of turbulence. The MIT Press, Cambridge, Massachusets, and London, England. Yaglom, A.M., & Monin, A.S., (1987), statistical Fluid Mechanics, The MIT Press, , Cambridge, Massachusets, and London, England. Siveertsen, T.H.,(2004) Invitation to Conceptual Discussions Concerning the Scope of the Scientific Method and Classification of Meteorological Phenomena and Meteorological Parameters, P 185-190, Selected Papers of the International Conference `Fluxes and Structures in Fluids", St. Petersburg, Russia, June 23-26, 2003, Moscow, IPM RAS, 2004 Sivertsen, T.H.,(2004), Discussing the Concept of Continuity of Continuum Mechanics, P 190-193, Selected Papers of the International Conference `Fluxes and Structures in Fluids", St. Petersburg, Russia, June 23-26, 2003, Moscow, IPM RAS, 2004 Sivertsen, T.H., (2004), Discussing the Concept of Turbulence and a Proposal of a Classification System of Fluid Dynamical Parameters, P 193-196, Selected Papers of the International Conference `Fluxes and Structures in Fluids", St. Petersburg, Russia, June 23-26, 2003, Moscow, IPM RAS, 2004 Sivertsen T.H., 2005, Discussing the scientific method and a documentation systems of meteorological and biological parameters, Physics and Chemistry of the Earth Special Issue: Agrometeorology 2003, Vol 30/1-3 pp 35-43 Sivertsen, T.H, 2005, ", Reflections on the Theme of Classifying, Documenting and Exchanging Meteorological Data", Atmospheric Science Letters, Vol.6 , Issue 3, p 171-175, John Wiley & Sons
Forfattere
Tor Håkon SivertsenSammendrag
Elements of the physical background of the phenomenon of internal gravity waves in the atmosphere are discussed , and the classical two-dimensional description of stationary waves is presented. Then the classical linearized system of equations is presented and discussed. The equation of wave energy of stationary waves of Eliassen & Palm (1961) is presented, as well as their statement of the conservation of the vertical flux of wave energy in a large class of systems. The special situation of a vertical layered atmospheric system with a discontinuity ( in the vertical direction) in the temperature of the air, the density of the air or the main stream) is considered. It is shown that the boundary conditions used by Eliassen & Palm (1961) sometimes violate their statement of conservation of the vertical flux of wave energy. References: Eliassen, A., & Palm, E., (1961), On the transfer of energy in stationary mountain waves, Geofysiske Publikasjoner, Oslo Sivertsen, T., (1976), On the transfer of energy in stationary mountain waves in an atmosphere with didcontinous parameters, Meteorologiske annaler Vol. 7 No. 3, Det Norske Meteorologiske Institutt Sivertsen T.H., 2005, Discussing the scientific method and a documentation systems of meteorological and biological parameters, Physics and Chemistry of the Earth Special Issue: Agrometeorology 2003, Vol 30/1-3 pp 35-43
Forfattere
Mekjell MelandSammendrag
Rain covers protect sweet cherries against rain cracking and reduce disease pressure. It is important in order to achieve high quality sweet cherries in many cherry-producing regions worldwide. Many different designs to variable costs are available at the market. Tree covers that are wind stable and economically feasible are a demand for the fruit growers.
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Conventional farmers converting to organics have contributed to most of the rapid expansion of organic farming in recent years. The new organic farmers may differ from their more established colleagues, which may have implications for the development of the organic farming sector and its distinctiveness vis-a-vis conventional production and marketing practices. The aim of this study was to explore Norwegian organic dairy farmers' personal and farm production characteristics, farming goals, conversion motives, and attitudes to organic farming, grouped by year of conversion (three groups). A postal survey was undertaken among organic dairy farmers (n=161). The results show that the newcomers (converted in 2000 or later) were less educated than the early entrants (the so-called 'old guard') who converted in 1995 or earlier. The frequency of activities like vegetable growing and poultry farming among the old guard was high. The late-entry organic herds were fed with more concentrates and had a higher milk production intensity, showed a higher incidence of veterinary treatments and less frequent use of alternative medicine than the herds of the two earlier converting groups. For all groups of farmers, the highest ranked farming goals were sustainable and environment-friendly farming and the production of high-quality food. Late entrants more often mentioned goals related to profit and leisure time. On average, the most frequently mentioned motives for conversion were food quality and professional challenges. The old guard was more strongly motivated by food quality and soil fertility/pollution issues than the others, whereas financial reasons (organic payments included) were relatively more important among the newcomers. All groups held very favorable views about the environmental qualities of organic farming methods, albeit with different strengths of beliefs. Even though trends towards more pragmatic and business-oriented farming were found, the majority of the newcomers were fairly committed.