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.
2021
Sammendrag
Inclusion of clover in grasslands increases functional diversity, N yield and forage quality and has been advocated for mitigating nitrous oxide (N2O) emissions. However, boreal grass-clover leys often show poor winter survival with considerable aboveground losses of nitrogen (N) and carbon (C). Little is known about how these losses affect off-season N2O emissions. Here we report field experiments over two winters, conducted at two coastal locations in Western and Northern Norway. N2O emissions were measured in plots with 0, 30 and 100% red (T. pretense) and white clover (T. repens) in a timothy - meadow fescue mixture. Overwinter N loss from the sward was quantified by comparing N contents in roots, stubble and herbage in autumn and spring. Additional treatments were removal of above-ground biomass in autumn and soil compaction. Off-season N2O emissions correlated positively with estimated overwinter N loss from herbage, which in turn depended on the fraction of clover in the ley. Pure grass leys emitted less N2O than leys that contained clover. Corrected for background emissions from pure grass, up to 13% of the above-ground N loss was emitted as N2O–N when clover was grown in pure stand. This fraction was much smaller, however, when clover was grown in mixture with grass (1.9 ± 0.9%), suggesting reassimilation of inorganic N. Indeed, we found significant increases in root and stubble N in mixtures throughout winter. Removal of above-ground biomass in autumn appeared to reduce the sward's ability to retain N throughout winter, and hence had no or a stimulating effect on N2O emissions. Soil compaction increased off-season N2O emissions 1.3–1.6-fold. Our results show that boreal grass-clover leys can be a significant source of N2O during winter, intricately controlled by loss and reassimilation of N. This underscores the importance of off-season plant-soil management for reducing the greenhouse gas (GHG) footprint of animal production in high latitude ecosystems.
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Utarbeidelse av skjøtselsplanen for de nordlige øyene i Hysværet i Vega kommune er utført på oppdrag av Statsforvalteren i Nordland. Skjøtselsplanen gir faglig funderte anbefalinger for skjøtsel av den trua naturtypen slåttemark, kystlynghei og naturbeitemark. Den baserer seg på feltbefaring med avgrensing av naturbase-lokaliteter og intervju med brukeren. Rapporten er delt inn i to hoveddeler. De første kapitlene gir en kort beskrivelse av naturtypene. Kapitlene 4-8 er rettet mot den som skal utføre skjøtsel, og omhandler natur-grunnlaget og dagens drift, samt beskrivelsen av konkrete restaurerings- og skjøtselstiltak innenfor lokaliteten. I vedlegg finnes en beskrivelse av de verdifulle naturtypelokalitetene som inngår i drifta og som er informasjons-grunnlaget for forvaltning, inkludert søkbare egenskaper for lokalitetene i Miljødirektoratets naturbase.
Sammendrag
Skjøtselsplanen for Kvalholmen i Vega kommune har blitt utarbeidet på oppdrag fra Fylkesmannen i Nordland, miljøvernavdelingen. Skjøtselsplanen gir faglig funderte anbefalinger for skjøtsel av kystlynghei, naturbeitemark og slåttemark på Kvalholmen. Skjøtselsanbefalinger tar hensyn til brukernes driftsopplegg, kapasitet og ønsker. Skjøtselsplanmalen er delt inn i ulike kapitler som bl.a. gir generell informasjon om aktuelle utvalgte naturtyper, generell beskrivelse av naturgrunnlaget innenfor lokaliteten og en beskrivelse av dagens drift.
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
It is not known to what degree growth and fruit yield are source-limited in everbearing strawberry plants. The growth and yield performance effect of bi-weekly removal of all runners and/or one or two leaves during the cropping season of tunnel-grown ‘Favori’ everbearing strawberry plants was determined. Plants were grown on a table-top system in an open plastic tunnel under natural light conditions in Norway from May to October. Removal of runners and leaves was bi-weekly from 5 June until 25 September. Fruits were harvested from 5 July to 7 October. Bi-weekly runner removal increased total and marketable yield and number and size of fruits, while increasing leaf thinning had the opposite effects. However, none of the treatments affected the fruit number and yield of the first fruiting flush. The treatments did not affect realization of the yield potential of the plants at planting, whereas the continued floral initiation and fruit growth were enhanced by runner removal. Increasing leaf thinning had the opposite effects. Both floral initiation and fruit growth in heavily flowering and fruiting everbearing strawberry are source-limited owing to the high fruit/leaf ratio of such plants.
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
The main objective was to evaluate to what extent subsoil compaction on an arable clay soil (Stagnosol (Drainic)) may be alleviated after 5 years under the climate conditions in South-East Norway. Therefore, field plots which had been ploughed and under minimum tillage were compacted through wheel impact (10x) with a 6.6 Mg wheel load. Samples were taken from the ‘compacted’ and ‘non-compacted reference’ treatments at depths of 40 and 60 cm both before and directly after compaction and again 5 years later. The soil physical parameters revealed that pre-compression stress, bulk density, air capacity, air conductivity and saturated hydraulic conductivity at depths of 40 and 60 cm were impaired by compaction, especially under ploughed. After 5 years, bulk density and pre-compression stress remained almost unchanged, while air capacity, air conductivity and saturated hydraulic conductivity had increased at both the 40 and 60 cm depth on both plots as compared to the compacted state and to R for the most part, indicating the recovery of the soil structure in the subsoil. The compaction status evaluated by the ‘compaction verification tool’ indicates the relative reduction of ‘harmful soil compaction’ (after wheel impact) with a change towards ‘slightly harmful compaction’ for the most part with an as yet limited saturated hydraulic conductivity at both depths after 5 years.
Sammendrag
Det er ikke registrert sammendrag