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.
2020
Forfattere
Joana Carvalho Cachapa Nicolai Vitt Meyling Meike Burow Thure Pavlo HauserSammendrag
Plants evolved in close contact with a myriad of microorganisms, some of which formed associations with their roots, benefitting from carbohydrates and other plant resources. In exchange, they evolved to influence important plant functions, e.g. defense against insect herbivores and other antagonists. Here, we test whether a fungus, Metarhizium brunneum, which is mostly known as an insect pathogen, can also associate with plant roots and contribute to above-ground plant defense. Cauliflower (Brassica oleracea var. botrytis) seeds were sown together with M. brunneum-inoculated rice grains, and the resulting plants subjected to leaf herbivory by the specialist Plutella xylostella. Activity of myrosinases, the enzymes activating glucosinolates, was measured before and after herbivory; larval consumption and plant weight at the end of experiments. Metarhizium brunneum clearly established in the plant roots, and after herbivory myrosinase activity was substantially higher in M. brunneum-treated plants than in controls; before herbivory, M. brunneum-treated and control plants did not differ. Leaf consumption was slightly lower in the M. brunneum-treated plants whereas total biomass and allocation to above- or below-ground parts was not affected by the Metarhizium treatment. Thus, M. brunneum associates with roots and primes the plant for a stronger or faster increase in myrosinase activity upon herbivory. Consistent with this, myrosinase function has been suggested to be rate-limiting for induction of the glucosinolate-myrosinase defense system. Our results show that M. brunneum, in addition to being an insect pathogen, can associate with plant roots and prime plant defense.
Sammendrag
In the Nordic countries Finland, Norway and Sweden, the most common regeneration method is planting after clearcutting and, often, mechanical site preparation (MSP). The main focus of this study is to review quantitative effects that have been reported for the five main MSP methods in terms of survival and growth of manually planted coniferous seedlings of Norway spruce (Picea abies (L.) Karst.), Scots pine (Pinus sylvestris L.) and lodgepole pine (Pinus contorta var. latifolia Engelm.) in clearcuts in these three countries. Meta analyses are used to compare the effects of MSP methods to control areas where there was no MSP and identify any relationships with temperature sum and number of years after planting. In addition, the area of disturbed soil surface and the emergence of naturally regenerated seedlings are evaluated. The MSP methods considered are patch scarification, disc trenching, mounding, soil inversion and ploughing. Studies performed at sites with predominately mineral soils (with an organic topsoil no thicker than 0.30 m), in boreal, nemo-boreal and nemoral vegetation zones in the three Fenno-Scandinavian countries are included in the review. Data from 26 experimental and five survey studies in total were compiled and evaluated. The results show that survival rates of planted conifers at sites where seedlings are not strongly affected by pine weevil (Hylobius abietis L.) are generally 80–90% after MSP, and 15–20 percent units higher than after planting in non-prepared sites. The experimental data indicated that soil inversion and potentially ploughing (few studies) give marginally greater rates than the other methods in this respect. The effects of MSP on survival seem to be independent of the temperature sum. Below 800 degree days, however, the reported survival rates are more variable. MSP generally results in trees 10–25% taller 10–15 years after planting compared to no MSP. The strength of the growth effect appears to be inversely related to the temperature sum. The compiled data may assist in the design, evaluation and comparison of possible regeneration chains, i.e. analyses of the efficiency and cost-effectiveness of multiple combinations of reforestation measures.
Forfattere
Lars Olav Brandsæter Kjell Mangerud Lars Andersson Trond Børresen Guro Brodal Bo MelanderSammendrag
There is a need both in organic farming and on farms using integrated pest management for non-chemical measures that control the perennial weed flora. The effect of mechanical weeding and fertilisation on perennial weeds, fungal diseases and soil structure were evaluated in two different experiments in spring cereals. Experiment I included six strategies. The first strategy was (1) without specific measures against perennial weeds. The other strategies encompassed one or two seasonal control measures; (2) rhizome/root cutting with minimal soil disturbance in autumn, (3) hoeing with 24 cm row spacing, (4) combined hoeing and disc harrowing in autumn, (5) ‘KvikUp’ harrowing in spring, and (6) ‘KvikUp’ harrowing in spring and autumn. Experiment II included factor (i) inter-row hoeing and (ii) fertilisation level. This experiment included the comparison between normal row spacing (12 cm) with weed harrowing versus double row spacing (=24 cm) in combination with inter-row hoeing and 4 fertilisation levels (50–200 kg N ha−1). In experiment I the strategies consisting of no or one direct weed control measure (1, 2, 3 and 5) clearly did not control the perennial weeds. The two seasonal control measures (4 and 6) gave a satisfactory weed control and highest crop yield. The combination of best weed control and no measured harmful effects on soil structure or increase of fungal diseases may explain the highest yields for these strategies. In Experiment II, hoeing and 24 cm spacing gave less perennial biomass compared to 12 cm spacing. Grain yields increased linearly with increasing nitrogen input. The study shows that both inter-row hoeing and weed harrows, are important elements in integrated pest management practice and organic farming. In addition, our results indicate that efficient mechanical weeding is possible without harmful effects in crop rotation consisting of various spring cereals as regards soil structure and plant health.
Sammendrag
Det er ikke registrert sammendrag
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Det er ikke registrert sammendrag
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Det er ikke registrert sammendrag
Sammendrag
De nordnorske produsentene står ovenfor nye utfordringer når dyrkingsteknikken endres til mer bruk av fiberduk. Fordelen er et bedre klima og bedre vekst, samt beskyttelse mot skadegjørere. Prosjektgruppa prøver å forstå mer om hvordan veksten påvirkes av kombinasjonen mellom temperatur og lys på våre breddegrader.
Forfattere
Eva Narten HøbergSammendrag
Det er ikke registrert sammendrag
Sammendrag
Sør-Varanger kommune i Øst-Finnmark har vært utsatt for luftforurensning fra russisk smelteverksindustri siden 1930-tallet, særlig fra smelteverket i byen Nikel som ligger bare ca. 10 km øst for den norske-russiske grensen ved Svanvik i Pasvikdalen. I tillegg til svoveldioksid inneholder utslippene store mengder tungmetaller, særlig kobber og nikkel. Formålet med denne undersøkelsen var å kartlegge tungmetallinnholdet i multer og blåbær og sammenligne nivået med tidligere studier. Resultatene fra innsamling i 2020 viser et tydelig geografisk mønster i innholdet av nikkel i blåbær og multer med til dels betydelig høyere konsentrasjoner i de delene av grenseområdet som er mest utsatt for forurensing. For kobber var variasjonsmønsteret mindre tydelig. På nær alle flater der vi har gjentak over tid finner vi også høyere konsentrasjoner av kobber og nikkel i 2020 enn i 1992, og 2008. Tidlig i 2020 kunngjorde russiske myndigheter at smelteverket i Nikel ville bli stengt i løpet av året. Bærinnsamlingen i 2020 er den mest fullstendige som er foretatt på norsk side i grenseområdet og er derfor et godt utgangspunkt for å overvåke tungmetallnivåene etter at smelteverket i Nikel er lagt ned.
Forfattere
Jørgen Todnem Tor LunnanSammendrag
I fjellbygdene er gode gårdsnære beiter vår og høst en nøkkelfaktor i saueholdet for god utnytting av utmarksbeitet, og tilfredsstillende lammevekter om høsten. Ved liten tilgang på fulldyrka beite, kan innmarksbeite gi tilfredsstillende beitekvalitet for sau vår og høst?