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.
2003
Forfattere
Svein Ole BorgenSammendrag
Many students of cooperative organizations have underscored that cooperatives are plagued by substantial incentive problems, so that members do not bear the full impact of their individual choices. It is argued that incentive problems are inherent in the cooperative form. I claim that the critique needs further clarification. The idea to be advanced here is that the validity of the critique raised from agency theory and property right theory rest with their ex ante assumptions about the nature of cooperative membership. The pivotal point is whether members are essentially ascribed the properties, reasoning and strategies of a rational investor or a rational user.
Forfattere
Svein Ole BorgenSammendrag
Det er ikke registrert sammendrag
Populærvitenskapelig – Rettleiingsprøving i italiensk raigras og raisvingel
Tor Lunnan, Lars Nesheim
Forfattere
Tor Lunnan Lars NesheimSammendrag
Rettleiingsprøvinga i engvekstar er lagt til forsøksseriar i forsøksringane. Resultat frå prøving av italilensk raigras som toårig vekst og prøving av raisvingelsortar er presentert. Italiensk raigras gav usikker overvintring og ser ut til å overvintre brukbart berre i ytre kyststrøk på Sør-Vestlandet. Overvintringa kan gå bra også andre stader, og ein kan vente med å pløye opp om våren til ein ser korleis vekstkrafta i graset er. I såingsåret har italiensk raigras gitt om lag 150 fôreiningar meir enn fleirårig raigras. Strålause sortar av italiensk raigras er aktuelle som undersådd i kornåker og gir bra gjenvekst og beite etter tresking. Nye sortar av raisvingel har gitt lovande resultat med overvintring og avlingar på høgde med fleirårig raigras og strandsvingel. Prøvinga held fram.
Forfattere
Pierre Ackerman Bruce TalbotSammendrag
Det er ikke registrert sammendrag
Sammendrag
Rhizosphaera spp. kan føra til sterkt nålefall på gran- (Picea spp.) og edelgran (Abies spp.). I nokre juletrefelt her i landet, spesielt i nordmannsedelgran (Abies nordmanniana), er dette eit så stort problem at sprøyting med kopar-preparat er nødvendig.
Forfattere
Erik Jautris Joner C. LeyvalSammendrag
Phytoremediation of organic pollutants depends on plant-microbe interactions in the rhizosphere, but the extent and intensity of such rhizosphere effects are likely to decrease with increasing distance from the root surface.We conducted a time-course pot experiment to measure dissipation of polycyclic aromatic hydrocarbons (PAHs) in the rhizosphere of clover and ryegrass grown together on two industrially polluted soils (containing 0.4 and 2 g kg(-1) of 12 PAHs). The impact of the fungal root symbiosis arbuscular mycorrhiza (AM) on PAH degradation was also assessed, as these fungi have previously improved plant establishment on PAH-polluted soils and enhanced PAH degradation in spiked soil.The two soils behaved differently with respect to the time-course of PAH dissipation. The less polluted and more highly organic soil showed low initial PAH dissipation rates, with small positive effects of plants after 13 weeks. At the final harvest (26 weeks), the amounts of PAHs extracted from nonplanted pots were higher than the initial concentrations. In parallel planted pots, PAH concentrations decreased as a function of proximity to roots.The most polluted soil showed higher initial PAH dissipation (25% during 13 weeks), but at the final harvest PAH concentrations had increased to values between the initial concentration and those at 13 weeks. An effect of root proximity was observed for the last harvest only. The presence of mycorrhiza generally enhanced plant growth and favored growth of clover at the expense of ryegrass. Mycorrhiza enhanced PAH dissipation when plant effects were observed.
Forfattere
S.C. Corgié Erik Jautris Joner C. LeyvalSammendrag
Rhizodegradation of recalcitrant organic pollutants, such as polycyclic aromatic hydrocarbons (PAH), may benefit from the major role that root exudates have on rhizospheric microbial processes. We investigated the influence of the proximity to ryegrass (Lolium perenne L.) roots on microbial populations and their biodegradation of phenanthrene (PHE) using compartmented pots. PAH degrading bacteria, total heterotrophic bacteria and PHE biodegradation were quantified in three consecutive sections at different distance (03, 36, 69 mm) from a mat of actively exuding roots.A bacterial gradient was observed with higher numbers of heterotrophs and PAH degrading bacteria closest to the roots. In parallel, a PHE biodegradation gradient was evident in the presence of roots. The biodegradation reached 86%, 48% and 36% of initially added PHE, respectively, in the layers 03 mm, 36 and 69 mm from the roots. The biodegradation rate was similar throughout the three layers of the non planted control. The present experimental system seems well suited for spatial and dynamic studies of PAH rhizoremediation.
Forfattere
Thomas Hartnik O. NordalSammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
The objective of this study was to provide empirical insight into dairy farmers’ goals, relative risk attitude, sources of risk and risk management responses. The study also examines whether organic dairy farming, leads to important risk sources not experienced in conventional farming and, if so, how those extra risks is managed. The data originate from a questionnaire survey of conventional (n=370) and organic (n = 160) dairy farmers in Norway. The results show that organic farmers have somewhat different goals than conventional farmers, and that the average organic farmer is less risk averse. Institutional risk was perceived as the most important source of risk, independently of conventional or organic production system, while organic farmers indicated greater concern about forage yield risk. Keeping cash on hand was the most important strategy to manage risk for all dairy farmers. Diversification and different kinds of flexibility was regarded as a more important risk management strategies among organic than conventional farmers.