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.
2022
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Weeds may reduce crop yields significantly if managed improperly. However, excessive herbicide use increases risk of unwanted effects on ecosystems, humans and herbicide resistance development. Weed harrowing is a traditional method to manage weeds mechanically in organic cereals but could also be used in conventional production. The weed control efficacy of weed harrowing can be adjusted by e.g. the angle of the tines. Due to its broadcast nature (both crop and weed plants are disturbed), weed harrowing may have relatively poor selectivity (i.e. small ratio between weed control and crop injury). To improve selectivity, a sensor-based model which takes into account the intra-field variation in weediness and “soil density” in the upper soil layer (draft force of tines), is proposed. The suggested model is a non-linear regression model with three parameters and was based on five field trials in spring barley in SE Norway. The model predicts the optimal weed harrowing intensity (in terms of the tine angle) from the estimated total weed cover and SD per sub-field management unit, as well as a pre-set biological weed threshold (defined as the acceptable total weed cover left untreated). Weed cover and SD were estimated with RGB images (analysed with custom-made machine vision) and an electronic load cell, respectively. With current parameter values, the model should be valid for precision weed harrowing in spring barley in SE Norway. The next step is to test the model, and if successful, adjust it to more cereal species. Weeds may reduce crop yields significantly if managed improperly. However, excessive herbicide use increases risk of unwanted effects on ecosystems, humans and herbicide resistance development. Weed harrowing is a traditional method to manage weeds mechanically in organic cereals but could also be used in conventional production. The weed control efficacy of weed harrowing can be adjusted by e.g. the angle of the tines. Due to its broadcast nature (both crop and weed plants are disturbed), weed harrowing may have relatively poor selectivity (i.e. small ratio between weed control and crop injury). To improve selectivity, a sensor-based model which takes into account the intra-field variation in weediness and “soil density” in the upper soil layer (draft force of tines), is proposed. The suggested model is a non-linear regression model with three parameters and was based on five field trials in spring barley in SE Norway. The model predicts the optimal weed harrowing intensity (in terms of the tine angle) from the estimated total weed cover and SD per sub-field management unit, as well as a pre-set biological weed threshold (defined as the acceptable total weed cover left untreated). Weed cover and SD were estimated with RGB images (analysed with custom-made machine vision) and an electronic load cell, respectively. With current parameter values, the model should be valid for precision weed harrowing in spring barley in SE Norway. The next step is to test the model, and if successful, adjust it to more cereal species.
Sammendrag
Management of Scots pine (Pinus sylvestris L.) in Norway requires a forest growth and yield model suitable for describing stand dynamics of even-aged forests under contemporary climatic conditions with and without the effects of silvicultural thinning. A system of equations forming such a stand-level growth and yield model fitted to long-term experimental data is presented here. The growth and yield model consists of component equations for (i) dominant height, (ii) stem density (number of stems per hectare), (iii) total basal area, (iv) and total stem volume fitted simultaneously using seemingly unrelated regression. The component equations for stem density, basal area, and volume include a thinning modifier to forecast stand dynamics in thinned stands. It was shown that thinning significantly increased basal area and volume growth while reducing competition related mortality. No significant effect of thinning was found on dominant height. Model examination by means of various fit statistics indicated no obvious bias and improvement in prediction accuracy in comparison to existing models in general. An application of the developed stand-level model comparing different management scenarios exhibited plausible long-term behavior and we propose this is therefore suitable for national deployment.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Torkild Jemterud Anne Sverdrup-Thygeson Einar Uggerud Gaute Einevoll Erik J. Joner Vidar Skogvoll Katharina VestreSammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Geir-Harald StrandSammendrag
The Copernicus high-resolution layer imperviousness density (HRL IMD) for 2018 is a 10 m resolution raster showing the degree of soil sealing across Europe. The imperviousness gradation (0–100%) per pixel is determined by semi-automated classification of remote sensing imagery and based on calibrated NDVI. The product was assessed using a within-pixel point sample of ground truth examined on very high-resolution orthophoto for the section of the product covering Norway. The results show a high overall accuracy, due to the large tracts of natural surfaces correctly portrayed as permeable (0% imperviousness). The total sealed area in Norway is underestimated by approximately 33% by HRL IMD. Point sampling within pixels was found to be suitable for verification of remote sensing products where the measurement is a binomial proportion (e.g., soil sealing or canopy coverage) when high-resolution aerial imagery is available as ground truth. The method is, however, vulnerable to inaccuracies due to geometrical inconsistency, sampling errors and mistaken interpretation of the ground truth. Systematic sampling inside each pixel is easy to work with and is known to produce more accurate estimates than a simple random sample when spatial autocorrelation is present, but this improvement goes unnoticed unless the status and location of each sample point inside the pixel is recorded and an appropriate method is applied to estimate the within-pixel sampling accuracy.
Forfattere
Berit Marie Blomstrand Heidi L Enemark Håvard Steinshamn Inga Marie Aasen Juni Rosann E. Johanssen Spiridoula Athanasiadou Stig Milan Thamsborg Kristin SørheimSammendrag
Background Eimeria spp. are widespread apicomplexan parasites known to cause coccidiosis in livestock, resulting in reduced animal welfare and productivity, particularly in sheep. The treatment options are limited, and there is an emerging development of resistance against registered pharmaceuticals. Spruce bark is rich in plant secondary metabolites (PSM), such as condensed tannins, which are bioactive compounds previously shown to have antiparasitic activity. Here, we examined the anticoccidial properties of bark extract of Norway spruce (Picea abies) against a field isolate of ovine Eimeria spp. by treating Eimeria-infected pre-ruminant lambs with water-extracted bark daily for 12 days. We hypothesised that the bark extract would reduce the faecal oocyst excretion and, consequently, the severity of diarrhoea. Results Oral administration of spruce bark extract significantly reduced the excretion of Eimeria oocysts in milk-fed lambs post treatment till the end of the trial 22 days post infection. This difference in oocyst excretion between the treated and the untreated infected animals increased with time. Compared to the untreated and the sham-infected control group, the group treated with bark extract had softer faeces and reduced milk intake during the treatment period. After discontinuing the treatment, the treated animals got a more solid and formed faeces compared to that of the untreated control group, and the milk intake increased to the level of the sham-infected, untreated control group. The bark extract treated animals had a lower body weight and a lower mean daily body weight gain throughout the whole duration of the experiment. Conclusions Bark extract from Norway spruce showed marked anticoccidial properties by reducing the faecal oocyst count and associated diarrhoea in young lambs. Simultaneously we experienced detrimental effects of the treatment, displayed as reduced feed intake and daily body weight gain. Therefore, we suggest conducting similar studies with lower bark extract dosage to explore the possibilities of a better trade-off to reduce the negative impact while maintaining the antiparasitic effect. Keywords: Coccidia, Coccidiocide, Eimeria, Industrial by-products, Sheep
Forfattere
Jessica Petereit Christina Hoerterer Adrian A. Bischoff-Lang Luís E. C. Conceição Gabriella Pereira Johan Johansen Roberto Pastres Bela H. BuckSammendrag
There is an increasing need in the aquaculture industry for more sustainable and functional feed concepts for marine finfish. This study provides results for the effect of alternative feed formulations on health status, welfare parameters, sensory analysis, and growth performance in European seabass (Dicentrarchus labrax) over an 83-day feeding trial. Fish were fed twice a day with five experimental diets. A control diet (control) and four different alternative feed concepts rich in processed animal proteins (PAP), other alternative ingredients (NOPAP), and a positive (NOPAP+) and negative (PAP−) formulation were tested. All alternative formulations contained hydrolysates from aquaculture by-products and macroalgae. The results indicate that the alternative feed concepts are more sustainable alternatives compared with the commercial diet. Equally interesting, the alternative formulations did not affect the sensory analysis of the fillet quality or the animal welfare. These are increasingly important factors in aquaculture products and, accordingly, also in the formulation of new feeds. Feed concepts that are not only more sustainable in their production, have shorter transportation distances, recycle the resources (usage of by-products), and have no adverse effect on growth or welfare parameters are highly needed. Therefore, the experimental diets tested in this study are a win-win concept for future seabass aquaculture production.
Sammendrag
Maarud fabrikker på Disenå ønsket å finne en god løsning på hvordan man kunne sirkulere ulike nærings avfall strømmer fra fabrikken. Komposteringsløsning ble valgt siden avfallet, som ikke er av animalsk opprinnelse, egner seg godt for kompostering og vil kunne bli til næringsrik kompost. Det biologiske avfallet som består av slam fra avløpsrenseanlegget, stivelse og ødelagt potet fra fabrikken er rent og en viktig ressurs å sirkulere. NIBIO har vært behjelpelig med å sikre en god og trygg prosess for kompostering av avfallet. Rapporten beskriver en risikovurdering av prosessen for å forhindre at mulig planteskadegjørere overlever kompostering og at en streng strategi for hygienisering er lagt til rette for drift av anlegget. Rapporten beskriver også oppbygningen av et komposteringsanlegg med fysisk inndeling i ren og ulike urene soner. God soneinndeling er en forutsetning for å sikre at ikke mulig smitte overføres til ferdig kompost. Rapporten beskriver en rekke laboratoriestudier hvor ulikt avfall er utprøvd i forskjellige blandingsforhold for å sikre temperatur over 55-70 °C over tilstrekkelig tid. Erfaringene fra laboratoriestudiene har deretter blitt utprøvd på store ranker som vendes slik at all masse eksponeres for høye temperaturer. Alle ranker overvåkes kontinuerlig med 4 trådløse temperaturfølere som sender data tilbake til kontrollrommet hvor informasjon kan logges på monitor og overføres til en database på PC. Operatørene følger daglig opp på prosessen slik at 100% av ranken holder seg over 55-70 °C både før og etter vendinger i 28 dager. Etter 2 års utprøving er det utviklet ulike resepter tilpasset sommer og vinter forhold. Slam mengden i resepten har blitt optimalisert slik at næringsinnholdet målt som Total N ligger på ca. 20 g/kg TS og Total P 6-7 g/kg TS. Over tid er det laget en empirisk modell for å vise hvor lang tid de ulike ranker skal ligge under aktiv fase, ettermodningsfase og til moden siktet kompost på ren grønn sone. Beregninger i modellen viser at prosessen trenger 33 uker fra avfallet blandes til komposten er ferdig modnet. Totalt ble det produsert 600 m3 kompost i prosjektet fra høsten 2020 til sommeren 2021 fordelt på 4 ulike batcher. Varedeklarasjoner for disse er laget og alle kompostbatcher har høy næringsverdi, kvalitets klasse 0 for innhold av tungmetaller og de inneholder ingen fremmedlegemer. Ingen cyster av PCN og patogene mikroorganismer er blitt påvist i noen av kompostrankene.