Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2007
Authors
Eivind Vangdal Stein Harald Hjeltnes Mekjell MelandAbstract
I eit felt med "Excalibur" og "Prinlew" plommer vart køyregangen dekka med kvit reflekterande duk for å betra ljostilhøva i trekruna. Duken låg i hagen frå 2 veker etter bløming til etter at plommene var hausta i midten av september. Der det ikkje var nytta reflekterande duk var fruktene nede på treet grønare, hadde mindre dekkfarge og lågare innhald av oppløyst turrstoff enn fruktene oppe i trekrunene. Fruktene frå tre som hadde stått over reflekterande duk var like godt farga og hadde same syrinnhald og fastleik om dei var hausta oppe eller nede på trea. Men det var også for desse trea høgare innhald av oppløyst turrstoff i fruktene oppe i trea i høve til dei som hadde vakse nedst i trea. Reflekterande duk gav jamnare mogning hjå plommene oppe og nede i trea. Dermed kan ein klara seg med færre haustingar. Temperaturen var ikkje heva der ein nytta duk, og duken svekka grasveksten i køyregangane.
Authors
Eivind Vangdal Stein Harald Hjeltnes Mekjell MelandAbstract
Betre lystilhøve i frukttrea aukar veksten hjå tre og frukter, og fruktkvalitetsfaktorar som farge og oppløyst turrstoff vert betre. Sjølv om daglengda under norske veksttilhøve er lang, er den samla lystilgangen mindre enn på sørlegare breiddegrader pga den korte vekstsesongen. Metodar som aukar ljostilgangen, t.d. lysreflekterande duk under trea, vil vera gunstig for norsk fruktdyrking. Ein har prøvd ein voven plast duk (Extenday (R)) i frukthagar på Vestlandet. Der radavstanden var 4 m, har ein strekt ut 3m brei duk på bakken langs køyregangane og festa med gummiband til trea på kvar side. Der radavstanden var 5 m, nytta ein 4m brei duk. Duken låg ute frå midten av juni til etter hausting. Det var ingen temepratureffekt av duken. Men det var 5 gonger så mykje lys i trekruna hjå tre som sto i felt med reflekterande duk i høve til kontroll tre. I køyregangen var det 3 gonger så mykje lys over duk som i køyregangar med gras. I Aroma var eple frå tre frå felt med duk større, søtare og med meir raud dekkfarge enn frå kontroll trea. Det var særleg stor skilnad frå eple på dei nedte greinene. Med omsyn til fastleik og syreinnhald var det ikkje sikre skilnader. Men Streif-indeks viste at refleksduken framskunda mogninga.
Authors
Kjersti Holt HanssenAbstract
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Abstract
The study aims to estimate the effects on the sheep farm economy of reducing grazing levels necessitated due to possible overgrazing by sheep on two important mountainous range pastures in southwest Norway. The pasture range in Setesdal Vesthei is grazed by sheep from distant farms located at Jæren (south of Stavanger), while south-western Hardangervidda is grazed by sheep from local farms and distant farms located along the coast. Farmers utilizing the pasture areas combine sheep with dairy cows, off farm work or businesses, while the local farms combine it with orchards. A Linear Programming (LP) model for specialized sheep farms based on farm records has been developed to study effects of reaching various grazing capacity levels. Reducing the number of sheep in Setesdal Vesthei by 10 percent would lower farm income per breeding stock animal with € 15 to € 119 and with € 35 to € 211 for Hardangervidda. The decrease in annual income will range from € 15,00 to € 119,00 in total for the farms using Setesdal Vesthei. The economic effects depend much on meat production per ewe. Replacing unilateral sheep grazing with a mixed system involving suckling goats and heifers is discussed to deal with the problems of encroachment and increasing elevation of the alpine tree-line.
Authors
Ståle Størdal Gudbrand Lien J. Brian HardakerAbstract
This paper presents empirical insight into part-time and full-time property owners’ perceptions of risk and risk management strategies. In addition, the relationships between forest owners with varying degree of off-property work and property and forest owner characteristics, risk perceptions, risk management strategies and harvesting behaviour are examined. The data originate from a questionnaire responded to by forest owners in eastern Norway which were merged with 9 years of logging data. Timber price variability and institutional risks were perceived as primary sources of risk. Use of advisers from the forest owners’ association, buying personal insurance and off-property work were perceived as the most important ways to handle risk. The results show that off-property work affects to a lesser degree what forest owners perceived as important risk sources, but that risk perceptions affect to a stronger degree the ways in which risk was dealt with. The chosen risk management strategies influenced the forest owner's harvesting behaviour to some extent, but more research on the issue is needed to clarify the relationship. There was a positive relationship between owners with off-property activities and their performance as timber suppliers. Several measures, such as improved rural education, revision of some of the arrangements that regulate property mergers and support measures for increased on-property diversification may increase annual timber harvesting and reduce variability in harvesting level.
Authors
Guro Ådnegard Skarstad Svein Ole BorgenAbstract
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Authors
Leif Jarle AsheimAbstract
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Authors
Guro Ådnegard Skarstad Svein Ole BorgenAbstract
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Authors
Lene Frost Andersen Trine Husøy Svein Olav Kolset Henrik Jakobsen Jan Alexander Mona-Lise Binderup Knut Helkås Dahl Erik Dybing Wenche Kristin Farstad Livar Frøyland Ragnhild Halvorsen Margaretha Haugen Kåre Julshamn Georg Kapperud Hilde Kruse Øyvind Lie Anne-Katrine Lundebye Helle Margrete Meltzer Judith Ann Narvhus Kristine Naterstad Ingolf Nes Bjørn Næss Jan Erik Paulsen Tore Sanner Janneche Utne Skåre Inger-Lise Steffensen Leif Sundheim Åshild KrogdahlAbstract
No abstract has been registered