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.
2008
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Goswin Heckrath Marianne Bechmann Petri Ekholm Barbro Ulen Faruk Djodjic Hans Estrup AndersenSammendrag
Compliance with the Water Framework Directive (WFD) will require substantial reductions in agricultural phosphorus (P) losses in the Nordic countries Denmark, Norway, Sweden and Finland. Falling P surpluses in agriculture for more than a decade and voluntary programmes of good agricultural practice have not reduced P losses to surface waters, while general regulatory measures have primarily focused on nitrogen. Without addressing the role of critical source areas for P loss, policy measures to abate diffuse P losses are likely to be ineffective. This has created a demand by environmental authorities for instruments that assess the risk of P losses from agricultural land and facilitate the planning of mitigation measures. In Nordic countries index-type risk assessment tools for diffuse P losses are under development inspired by experiences with P indexing in the USA. A common feature is that they are empirical, risk-based, user-friendly decision tools with low data requirements. Phosphorus indices vary between the four Nordic countries in response to different agriculture, soil and climate. These differences also result in different recent average annual agricultural P load estimates to the sea of 0.3, 0.5, 0.5 and 1.1 kg total P ha1 in Denmark, Norway, Sweden and Finland, respectively. In initial evaluations, Nordic P indices explained a large degree of variance in P losses at the field or catchment scale, but comparative data are still limited. To gain acceptance amongst stakeholders and inform river basin management planning in Nordic catchments as part of the WFD, it is crucial to more thoroughly evaluate the performance of these indices" at the field and catchment scale.
Forfattere
Trygve S. Aamlid Oleif Elen John Ingar Øverland Stein Kise Jørn K. Brønstad Trond Olav Pettersen Ove HetlandSammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
I middel for to forsøk i 2007 ble det oppnådd mer kompakte planter og usikre meravlinger for vekstregulering i frøeng av alsikekløver, mest etter sprøyting med dosen 30 ml/daa på knoppstadiet. Flere forsøk er nødvendig før å kunne gi sikre råd om vekstregulering i alsikekløver.
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Tree-killing bark beetles conquer healthy trees by means of pheromone mediated mass-attacks. The initial attackers select trees through a process of random landing and processing of tactile and short-range chemical stimuli. Inside acceptable hosts they produce aggregation pheromones that attract additional attackers. In a recent field experiment we induced defense responses in 60-year-old Norway spruce trees and monitored colonization by the spruce bark beetle Ips typographus. Induced stem sections had significantly less beetle colonization than control sections, with shorter parental galleries and fewer eggs deposited. In addition, fewer beetles were attracted to beetles tunnelling in induced bark. This reduced ability to attract conspecifics suggests that induced host defenses interfere with beetle pheromone production or emission. The mechanisms responsible for this are unknown, but may involve emission of volatile terpenes such as (E)-b-farnesene and linalool, which have been shown to increase up to 100-fold in induced Norway spruce trees. These compounds have been reported to attract natural enemies of herbivores or repel herbivores directly in other conifer-insect interactions.
Sammendrag
From 2002 to 2007, the number of organic farms in Norway has increased slightly, from 2303 to 2611. The area of organically certified and in conversion farmland has increased much more, from 32,499 to 49,563 ha. Hence, the average size of organic farms has increased considerably, from 19.7 to 25.5 ha agricultural area per farm. This is 20 % above the Norwegian average farm size. As parallel production is permitted, many farms have both organic and conventional production. The average organically managed agricultural area has increased from 11 to 15.4 ha per farm, and the number of milking cows on organic dairy farms from 15 to 20. Many small farms have opted out of certified organic agriculture, whereas farmers with more land are converting to organic. While most of the public financial support in Norwegian agriculture is differentiated in relation to farm size and region, support for organic agriculture is little differentiated. This encourages the conversion of larger operations. However, the diversity of the organic sector is reduced when smaller farms do not convert or opt out, and it should be considered how organic farming can be an interesting option for farmers independent of farm size.
Forfattere
Helge SjursenSammendrag
Burot tilhører den biologiske gruppen flerårig stedbundne ugras med rotstokk.Den voksne planten er 0,5 " 2,0 m høy, med tykk, treaktig rotstokk. Stengelen er opprett, grov, ofte rødbrun. Bladene er finnete med spisse småblad. Basale blad er kortstilkete, stengelblad sittende og stengelomfattende. Oversiden er mørkegrønn, undersiden kvitfiltrert. Blomsterkorgene sitter i mange aksliknende klaser fra bladhjørnene. Formeringen og spredningen skjer mest ved frø (opptil 700 000 pr. plante), men også ved at nedre del av stenglene slår røtter, og ved mekanisk oppdeling av rotsystemet. Forekommer på dyrket og udyrket mark, på veikanter, langs gjerder og hekker, på tomtearealer og avfallsplasser. Liker varm jord, rik på kalk og næring. Opptrer som ugras i åker, eng og beiter. Pollenet er sterkt allergifremkallende. Burot kan motarbeides ved avhogging før blomstring, og oppstikking av rotstokken. Fenoksypropionsyrer har bra virkning, mens MCPA og sulfonylureapreparater er svake.