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
Forfattere
Anne Kristine Søvik Pål Tore MørkvedSammendrag
Constructed wetlands (CWs) in the agricultural landscape reduce non-point source pollution through removal of nutrients and particles. The objective of this study was to evaluate if measurements of natural abundance of 15NO3 " can be used to determine the fate of NO3 " in different types of small CWs treating agricultural runoff. Nitrogen removal was studied in wetland trenches filled with different filter materials (T1 " sand and gravel; T3 " mixture of peat, shell sand and light-weight aggregates; T8 " barley straw) and a trench formed as a shallow pond (T4). The removal was highest during summer and lowest during autumn and winter. Trench T8 had the highest N removal during summer. Measurements of the natural abundance of 15NinNO3 " showed that denitrificationwas not significant during autumn/winter, while it was present in all trenches during summer, but only important for nitrogen removal in trench T8. The 15N enrichment factors of NO3 " in this study ranged from"2.5 to "5.9"(T3 and T8, summer), thus smaller than enrichment factors found in laboratory tests of isotope discrimination in denitrification, but similar to factors found for denitrification in groundwater and a large CW. The low enrichment factors compared to laboratory studies was attributed to assimilation in plants/microbes as well as diffusion effect. Based on a modified version of the method presented by Lund et al. [Lund LJ, Horne AJ, Williams AE, Estimating denitrification in a large constructed wetland using stable nitrogen isotope ratios. Ecol Engineer 2000; 14: 67"76], denitrification and assimilation were estimated to account for 53 to 99 and 1 to 47%, respectively, of the total N removal during summer. This method is, however, based on a number of assumptions, and there is thus a need for a better knowledge of the effect of plant uptake, microbial assimilation as well as nitrification on N isotopic fractionation before this method can be used to evaluate the contribution of dinitrification in CWs.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
C Rahn K Zhang R Lillywhite C Ramos J de Paz J Doltra Hugh Riley M Fink C Nendel K Thorup-Kristensen A Pedersen F Piro A Venezia C Firth U Schmutz F RaynsSammendrag
The production of fresh vegetables within Europe relies on intensive rotations, supported by large inputs of nitrogen from fertiliser and organic sources which is required to maintain the yield and quality of produce demanded by the multiple retailers and their customers. Most field vegetable crops use nitrogen inefficiently and often leave large residues of nitrogen (either as unused fertiliser or crop debris) in the soil after harvest, which can potentially cause damage to soil, water and aerial environments. Funding from the EU Commission has enabled the development of a new computer model, EU-Rotate_N, which can be used to investigate the fate of nitrogen supplied to rotations of field vegetable crops. EU-Rotate_N was used to examine the effects of applying existing codes of Good Agricultural Practice (GAP) on the economic and environmental performance of several case study rotations in Europe. In some cases, following GAP, led to significant reductions in N losses without affecting the farmer"s gross margin but in others reduced gross margin without reducing N losses significantly. This paper will briefly describe the development of the model and will present the results of several case studies to show the effects of applying GAP on the performance of horticultural rotations.
Sammendrag
In the last few decades, it has been noted that the epiphytic lichen Usnea longissima appears to be declining in numbers throughout its previous distribution range in Scandinavia. Up until now, clearcutting forestry has been considered the main threat to its persistence. Suspecting that other threats also may be at work, we studied the fate of 20 U. longissima localities in undisturbed forest stands, surveyed in 1994–95 and subsequently in 2003–04, in the Nordmarka region, north of Oslo, Norway. Yearly λ was calculated to be 0.94 (95% CI = 0.91-0.97), both with respect to number of trees bearing the lichen and total number of thalli per locality. This corresponds to a 10-year decline of 46%, or a half-life of 11 years. No new establishments were recorded. Now being listed as Endangered (EN) in the revised Norwegian Redlist of 2006, all known localities will be protected from major forestry operations. However, without knowledge of additional threat sources, its future possibility for survival looks bleak. Possible negative factors are discussed, including air pollution, increasing tree canopy closure, inter-specific competition, and genetic depauperation.
Forfattere
Arne HermansenSammendrag
Utfordringen plantesjukdommer og produksjon av kvalitetsløk
Forfattere
Nils VagstadSammendrag
Det er ikke registrert sammendrag
Forfattere
Hans StabbetorpSammendrag
Foredraget gir en oversikt over hva som har skjedd på verdensmarkedet for korn og utviklingen på korn i Norge, spesielt når det gjelder hvete. Langvarige og kontinuerlige undersøkelser som er i gang må videreføres. De største utfordringene for FoU blir omtalt. Dokumentasjon av kvalitet i utvidet forstand og hvordan de ulike komponentene varierer med ulike sorter og under ulike dyrkningsforhold blir meget viktig. Dette må videre utnyttes ved riktig logistikk, sortering, lagring og bruk. Ny teknologi, sensorer og modeller for korndyrking på større enheter og varierte dyrkningsforhold må utvikles og tas i bruk.
Forfattere
Lars Olav BrandsæterSammendrag
Det er ikke registrert sammendrag
Forfattere
Ellen Johanne SvalheimSammendrag
Grenda Rygnestad er foreslått som utvalgt kulturlandskap for Aust-Agder. I grenda er det registrert en rekke kulturminner, og flere verdifulle naturtypelokaliteter med kulturavhengige arter er også registrert. Denne forvaltningsplanen vektlegger driften av landskapet og naturverdiene innen området. Spesielt legges det vekt på skjøtsel av de verdifulle biomangfoldlokalitetene.
Forfattere
Ellen Johanne SvalheimSammendrag
Grenda Åraksbø er foreslått som utvalgt kulturlandskap for Aust-Agder. I grenda er det registrert en rekke kulturminner, og flere verdifulle naturtypelokaliteter med kulturavhengige arter er også registrert. Denne forvaltningsplanen vektlegger driften av landskapet og naturverdiene innen området. Spesielt legges det vekt på skjøtsel av de verdifulle biomangfoldlokalitetene.