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
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
Paul Hatcher Lars Olav Brandsæter G. Davies A. Luscher HL Hinz R. Eschen U. SchaffnerSammendrag
The increasing problems caused by Rumex (especially R. obtusifolius L., R. crispus L., and R. longifolius DC.) infestation to organic agriculture in Great Britain, Norway and Switzerland are discussed. Here, inadequate, costly or time-consuming non-chemical control options for Rumex are one of the major barriers for farmers converting to organic production. Potential biological control agents for Rumex in Europe are discussed. We conclude that the chrysomelid beetle Gastrophysa viridula Degeer and the rust fungus Uromyces rumicis (Schum.) Wint. remain the most promising of the researched indigenous species, and that G. viridula can be combined with non-chemical control methods. However, there is a need for biocontrol agents that target Rumex roots; several sesiid moth species are present in Europe which feed upon these, and we suggest that one, Pyropteron chrysidiformis (Esper), has good potential for Rumex biocontrol and merits further study within Europe.
Sammendrag
Forskningsresultater innenfor forebyggende og direkte tiltak for kontroll av rotugras i økologisk korndyrking ble gjennomgått. I løpet av kort tid vil det bli etablert en "link" til PDF filer med presentasjonene fra møtet i Rygge 27. novemer 2007.
Forfattere
Jan NetlandSammendrag
Fleire viktige ugrasmiddel i gønsaker blir borte fra marknaden om eit år. Det er lite nye middel prøving, men i krossblomstra kulturer og i gulerot blir Command og Boxer klomazon prøvd ut.
Forfattere
Espen GovasmarkSammendrag
Omhandler essensielle næringsstoffer med spesiell fokus på essensielle mikromineraler til planter og husdyr (jern, sink, mangan, kopper, molybden, kobolt, selen). Temaer som ble omtalt var status i dag, mulige problemer pga mikromineralmangel og mulige løsninger på prblemene.
Forfattere
Espen GovasmarkSammendrag
Besvarer spørsmålet "Kan biorest og kompost av matavfall brukes i økologisk landbruk?", og svaret er JA, men de må oppfylle spesifikke krav mhp kvalitet og produksjonsmåte.
Forfattere
Espen Govasmark Mark G. GrimmettSammendrag
An existing laboratory procedure for selenium analysis using open-vessel wet digestion and liquid chromatographic fluorescence determination was modified for use with microwave digestion. The proposed microwave digestion method eliminated the hazards associated with the use of HCIO4 while maintaining excellent recoveries of selenium. A 2-step HNO3/H2O2 digestion procedure was developed. Digested samples were derivatized with 2,3-diaminonaphthalene, and the resultant piazselenol complex was measured fluorometrically using a liquid chromatograph. Measured values were in agreement with 9 different certified reference materials. The detection limit for this method was 0.54 ng Se/g tissue (3 s), and the calibration curve remained linear (r2 = 0.9968) up to 2 mg Se/g.
Forfattere
Maria HerreroSammendrag
Symptomer på P.ramorum på diverse vertplanter.
Forfattere
Agnethe ChristiansenSammendrag
A presentation of work at Bioforsk Laboratory. Multimethods for pesticide residue analysis of food of plant origin and water. Results of the 2005 monitoring programme.