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.
2007
Forfattere
Kjell Mangerud Lars Olav Brandsæter Kjell WærnhusSammendrag
The objective of the ongoing study is to obtain new knowledge to provide a fundament for improving weed harrowing in organic cereal production as well as optimising weed harrowing as an alternative for herbicides in conventional farming. Results from field experiments on three locations during three years will be presented and discussed. The experiments included the factors: a) different manufactures of spring tine weed harrows, type of tines and used with different aggressiveness (adjusted through tine working depth and speed); b) cereal developmental stages; and c) soil types (locations) and conditions as well as weed infestation levels. The project included new experimental equipment including a specially constructed 1.5 meter wide harrow, which made it possible to treat many small sub-plots. Cereal yield and quality, number and dry matter weight (biomass) of weeds, and soil water content, soil share strength, and soil penetration resistance were recorded. The resulting intensity of the harrowing operation was measured using digital pictures taken before and after harrowing to give an estimate of cereal coverage of the soil. Pre-emergence harrowing and harrowing at early 1-leaf crop stage reduced in general weed number and biomass compared to untreated control. The mean weed reduction over locations and years was about 40%, but this reduction was not always significant different to control plots. In one year, harrowing at those early stages gave an increase in weed number and biomass, presumably because of rainy weather after harrowing. In general, pre-emergence harrowing and harrowing at early 1-leaf stage increased crop yield compared to untreated, but harrowing at such stages occasionally also resulted in small yield reductions. We conclude, however, that this early harrowing should be carried out every year. Weed harrowing once, either at 2 or 3-4 crop leaf stages, also gave decreased weed number and biomass, but no clear influence on cereal yield. Therefore, harrowing at these late stages is an opportunity, if weather conditions do not allow weed harrowing at earlier stages. The combination of pre-emergence harrowing and harrowing at 3-4 leaf stage gave a significant reduction of weed number and biomass compared to untreated control. In general, harrowing twice gave increased crop yields, but the differences were only significant at one of the locations. The potential benefit of a second harrowing at the 3-4 leaf stage depends on the weed situation, number and biomass, as well as crop competitiveness. Our results have indicated that the threshold for weed harrowing may be around 300 annual weeds m-2, but more knowledge is needed for verifying the level of total number and species. If the number of weeds is less, weed harrowing twice gives a significant reduction in weed number, but not an increase in yield compared to only one weed harrowing at an early growth stage. Furthermore, our results indicate that the different types of harrows and tines will not work properly on all soil types. On light soils, all of them gave satisfying results. However, a normal tine (" 7mm bent Einböck or a " 10mm long straight CMN) is not rigid enough on soil types that build a soil crust after rain. An " 8mm bend Einböck tine, however, was better at breaking a soil crust and thereby improve cereal plant emergence on such soils. On the other hand, it is important not to adjust such tines too aggressive when no crust is present. Another trial showed that a straight tine will pick up less stones on stony soils than a bent one will do, stones which might damage the combiner during combining. Our results from one of the locations (medium light soil with stones) showed that yield as well as reductions in weed number or biomass m-2 was not affected by tine type.
Forfattere
Helge SjursenSammendrag
De viktigste biologiske gruppene er: Sommerettårige, vinterettårige, toårige, flerårig og stedbundne ,og flerårig og vandrende arter.
Forfattere
Solveig HaukelandSammendrag
De fleste av oss har, enten vi har hage, dyrket mark eller ferdes i skog og mark, hatt befatning med iberiaskogsneglen, brunsneglen, mordersneglen, rambosneglen. Mange navn på en etter hvert velkjent skapning i hagene våre. Sneglene tar godt for seg av plantene blomsterbedet, og man kvier seg for å gå barbeint over en duggfrisk villaplen en sen sommerkveld. Salat- og jordbærbøndene har ennå mer å frykte, eller? Foredrag om iberiaskogsnegl levesett og bekjempelse.
Forfattere
Trond HofsvangSammendrag
Det er ikke registrert sammendrag
Forfattere
Helge Sjursen Lars Olav BrandsæterSammendrag
Generelt kan en si at frøbank er summen av levedyktige frø nedi jorda, både de som er mer eller mindre i hvile (dormante) og de som er spiredyktige umiddelbart. Frø på jordoverflata regnes ofte også som en del av frøbanken.
Forfattere
Helge SjursenSammendrag
Frøugrasfrøbanken: * "Forteller" noe om driften. * Forhindre frøsetting mest mulig, både i selve grønnsakkulturen og i "saneringskulturen" * Alltid en balansegang mellom ugrasutviklingen og kostnadene ved ugraskontrollen Rotugras: * Rotugrasfrøbank utgjør bare 2-3% av total frøbank * Rotugraset bør bekjempes mest mulig i "saneringskulturen
Forfattere
Trond HofsvangSammendrag
Artikkelen inneholder minneord om Gudmund Taksdal og hans innsats innen anvendt entomologi, både innenfor norsk jord- og hagebruk og internasjonalt. En oversikt over Taksdals entomologiske publikasjoner fra 1957 til 2003 er også gitt.
Forfattere
Richard MeadowSammendrag
Foredraget omhandlet resultater fra to kålflueprosjekter og fra middelprøving.
Forfattere
Trond HofsvangSammendrag
Artikkelen gir en kort innføring i insektenes rolle i film. Den omhandler ikke insekter i dokkumentarfilmer, men spillefilmer der insekter inngår som en del av handlingen. Dessverre er insektenes medvirkning svært ofte begrenset til sjangeren "skrekkfilm".
Forfattere
Trond HofsvangSammendrag
Her gis en oversikt over en del sommerfuglarter som formerer seg lenger sørover i Europa, men som enkelte år migrerer nordover til Norge i store mengder.