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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

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Norway has vast rangeland resources (292,361 km2) with an estimated carrying capacity of nearly four million sheep and lambs, twice the current number. However, the intensive production system currently applied has led to more concentrate dependency, resulting in heavier animals in addition to poorer utilization of rangelands and homegrown feed. Intensive feeding systems indirectly influence the sustainability of ecosystems by promoting intensive cropping that can deplete soil fertility and threaten landscape preservation and biodiversity. By contrast, extensive grazing systems can produce environmentally and animal-friendly food products and contribute to regulating soil health, water and nutrient cycling, soil carbon sequestration, and recreational environments. In this paper, the economics of current sheep feeding practices in Norway, using a linear programming model, were compared with more extensive systems which allow for higher usage of on-farm feed resources. Changes in current sheep farming practices have the potential to increase lamb meat production relative to mutton production, in addition to improving the year-round supply of fresh meat. The investigated alternatives, using the Norwegian White Sheep (NWS) breed, suggest that delayed lambing is useful only on farms with abundant pastures available for autumn feeding. Lambs achieve a better market price than hoggets and mature sheep. Therefore, based on the current Norwegian meat market and price offered per kilogram of meat for lamb, an increase in NWS lamb production improves farm profits. On the other hand, when the aim is on greater use of homegrown feed and rangelands, this can be achieved through hogget production, and the quantity of concentrates required can be reduced substantially.

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Rotgall nematoder (Meloidogyne spp.) er globalt de mest skadelige nematodene, og forårsaker mer enn 10 % av avlingsreduksjonen på verdensbasis. M. arenaria, M. javanica, M. incognita og M. hapla er de viktigste artene. Totalt er det beskrevet mer enn 90 arter av otgallnematoder, og av disse er ca. 20 så langt blitt funnet i Europa. M. chitwoodi and M. fallax betraktes som en trussel for Europa og begge artene forårsaker alvorlige kvalitetsskader på potet og grønnsaker som gulrot. På det europeiske kontinentet er M. hapla mest utbredt, mens M.chitwoodi og M. fallax er påvist i begrensede områder....

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Jordfabrikken AS er et nytt foretak etablert i Verdal, Trøndelag med mål om å lage torvfri hagejord basert på kompost. Jordfabrikken sitt anlegg huser 2 store 125 m3 komposteringsreaktorer. Reaktorene sørger for nedbryting av biologiske materialer i et lukket system som går automatisk kun med behov for daglig påfylling. Reaktorene kan lett styres for antall daglige omdreininger og mengde luft som er tilsatt med trykk for å sørge for optimal kompostering. I forbindelse med oppstart og drift av anlegget ble NIBIO engasjert til å gi faglige råd om hvordan reaktorene bør styres for å oppnå en tilstrekkelig komposttemperatur og for at sluttproduktet skulle bli stabilt. I begynnelsen av oppdraget lå gjennomsnittlig temperatur i reaktor 1 og 2 på 44 °C. Målet var å få høy nok temperatur, i området 55-70 °C, for optimal kompostering og for å imøtekomme hygieniseringskrav (14 dager >55° eller 48 timer >60 °C). Råstoffmiks brukt i reaktorene består av hageavfall, pappslam, og kornavrens….

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Use of big bale silage and haylage can be difficult on farms where daily forage consumption is comparatively low as speed of deterioration of forage after bale opening may be faster than feed‐out rate. Production of smaller bales at harvest is possible, but expensive and work‐intensive. Therefore, a pilot study of rebaling forage stored in big bales to smaller bales was conducted. Three separate experiments were included, where microbial and chemical composition of silage and haylage was studied before and after rebaling. In Experiment III, residual big bale forage stored and opened together with rebaled forage was included. Results showed that rebaled haylage and silage had higher yeast counts compared to initial forage; however, residual bales in Experiment III had yeast counts similar to rebaled forage, indicating an effect of storage time rather than of rebaling. In Experiment II, mould counts were higher in rebaled compared to initial silage, but not in haylage. Chemical composition was similar in initial and rebaled forage except for ammonia‐N. In Experiment III, ammonia‐N was higher in rebaled compared to initial and residual forage and was the only chemical variable affected by rebaling. Bale temperature during aerobic storage followed ambient temperature until day 6–8 in Experiment I and until day 14 in Experiment III where ambient temperature was lower. In conclusion, rebaling can be done without large changes in chemical composition of the forage, but yeast and mould counts may be higher in rebaled forage, and this risk should be considered when using this procedure.

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Many of the world’s peatlands have been affected by water table drawdown and subsequent loss of organic matter. Rewetting has been proposed as a measure to restore peatland functioning and to halt carbon loss, but its effectiveness is subject to debate. An important prerequisite for peatland recovery is a return of typical microbial communities, which drive key processes. To evaluate the effect of rewetting, we investigated 13 fen peatland areas across a wide (>1500 km) longitudinal gradient in Europe, in which we compared microbial communities between drained, undrained, and rewetted sites. There was a clear difference in microbial communities between drained and undrained fens, regardless of location. Community recovery upon rewetting was substantial in the majority of sites, and predictive functional profiling suggested a concomitant recovery of biogeochemical peatland functioning. However, communities in rewetted sites were only similar to those of undrained sites when soil organic matter quality (as expressed by cellulose fractions) and quantity were still sufficiently high. We estimate that a minimum organic matter content of ca. 70% is required to enable microbial recovery. We conclude that peatland recovery after rewetting is conditional on the level of drainage-induced degradation: severely altered physicochemical peat properties may preclude complete recovery for decades.

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Calcareous grasslands are rich in biodiversity and thus receive much attention in nature conservation. In such grasslands, the formation of moss layers is perceived as a management problem. However, its impacts on the community level are complex, as not only inhibition but also facilitation of vascular plant recruitment occur. Possible filters of recruitment are shading by mosses, isolation from soil resources and the resulting desiccation. To understand how seed size and shape moderate moss effects, a combined glasshouse and field experiment was conducted in southern Germany. Seeds of 14 species from calcareous grasslands were sown either on top or underneath a moss layer, or on bare soil without moss. We determined the total number of emerged and established seedlings, i.e. the ones that survived until the end of the experiment. Both measures were reduced for most species sown on moss, while mortality was slightly enhanced by moss presence. Seed size explained a significant proportion of the moss effects on plant recruitment. Inhibitive effects on recruitment increased with seed size when seeds were placed on top of moss. When germinating underneath moss, the effect on emergence changed from negative in small-seeded plant species to positive in large-seeded species, but this effect was insignificant for establishment. The positive response in large seeds was probably due to their higher moisture requirements for imbibition, and lower dependency on light for germination. However, moss-seed-interactions were not affected by seed shape. Seedling establishment of plants with large seeds strongly depended on their initial position in moss, while small-seeded species showed no effect. Hence, moss layers constitute a selective recruitment filter by modifying seed penetration and hence germination conditions. This effect could increase beta diversity of vascular plant species in calcareous grasslands, and thus conservation should aim at intermediate and patchy moss abundance.