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.
2016
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Large areas of cultivated grasslands are annually abandoned and no longer used for production in Norway. Such areas will over time be encroached by shrubs and trees. Knowing that access to spring and autumn pastures is a limiting factor for sheep farmers, we tested the effect of grazing abandoned grassland on sheep production. We also assessed herbage production by looking at plant community development, pasture production, herbage quality and pasture utilization by sheep and heifers. The experiment was run for two consecutive years; 2014 and 2015. The sheep production was assessed by studying one sheep flock with 83(88) ewes(lambs) in 2014 and 77(106) ewes(lambs) in 2015, which was assigned each year with respect to age of ewe and number of lambs born to three treatments: 1) control; common farm procedure with short spring grazing period before summer grazing on range pasture, 2) spring extended; 4 weeks extended spring grazing period on abandoned cultivated grassland before summer grazing on range pasture, 3) whole season grazing on abandoned grassland. Assessment of herbage production was done by sheep grazing the whole area for one month in spring and autumn. During the summer, the area was assigned to three replicated treatments: a) control with no management, b) grazing heifers and c) grazing sheep with offspring. The stocking rate was 1.8 LU/ha, in both b and c, for a duration of one month. Pasture production and herbage intake was estimated using grazing exclosure cages. Weight gain from birth to autumn as well as slaughter weight were significantly (P<0.05) higher in lambs assigned to treatment 2 with four weeks extended spring grazing period (259 g/day and 15.7 kg) compared to treatment 1 (238 g/day and 14.3 kg) and treatment 3 (216 g/day and 13.2 kg). Herbage consumed during the summer period was on average 211 g DM/m2 and the pasture utilization was 55%. The annual consumption and utilization was 336 g DM/m2 and 62% in the grazed treatments and 28 g DM/m2 and 15% in the control, respectively. Total annual pasture production was on average 72% higher in the grazed treatments compared to the control. There was no difference between the grazed treatments on annual herbage production, herbage intake or pasture utilization. The use of abandoned cultivated grassland for extended spring grazing improved weight gain and slaughter weight of lambs. Further, grazing stimulated herbage production
Sammendrag
Large areas of cultivated grassland are annually abandoned and no longer used for production in Norway. Such areas will over time be encroached by shrubs and trees, which is regarded as undesirable. We assessed plant community development, pasture production, herbage quality and pasture utilization by sheep and heifers of a grassland that has been unmanaged for 12 years. e experiment was run for two consecutive years. Sheep grazed the whole area for one month in spring and autumn. During the summer, the area was assigned to three replicated treatments: (1) control with no management; (2) grazing heifers; and (3) grazing sheep with offspring. The stocking rate was 1.8 LU ha-1, in both b and c, for a duration of one month. The area was left resting for a month aer treatment and before autumn sheep grazing. Pasture production and herbage intake was estimated using grazing exclosure cages. Herbage consumed during summer period was on average 211 g DM m-2 and the pasture utilization was 55%. The annual consumption and utilization was 336 g DM m-2 and 62% in the grazed treatments and 28 g DM m-2 and 15% in the control, respectively. Total annual pasture production was on average 72% higher in the grazed treatments compared to the control. Tere was no difference between the grazed treatments on annual production, herbage intake or pasture utilization. Grazing stimulated herbage production, and such abandoned grasslands are valuable forage resources.
Forfattere
Lars Olav BrandsæterSammendrag
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Sammendrag
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Forfattere
Sarah Calvache Gil Tatsiana Espevig Erik J. Joner T.E. Andersen Trond Olav Pettersen Trygve S. AamlidSammendrag
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Sammendrag
Norway spruce (Picea abies (L.) Karst.) understory seedlings, growing in partially harvested plots with different canopy cover in a boreal spruce stand, were spot fertilized (Hydro 15-4-12) 9 years after planting. The principal aimwasto test the hypothesis that nitrogen (N)availability influences growthof understory seedlings at intermediate but not at lowlevels of irradiance. In addition, we tested the combined influences of N and light availability on selected morphological and phenological traits, covering a 2-year period after treatment. Diffuse radiation (DIFR) at the seedling level was estimated from hemispherical photographs and ranged from 19 to 46 per cent of DIFR in openconditions. Fertilizer applicationwasassociatedwithamarkedincreasein foliarNconcentration.Thefertilized seedlings grew better in height and root collar diameter compared with unfertilized controls. While the absolute growth in both diameterand height increased with increasing DIFR, seedlings also responded to improved nutrient availability across the rangeof light conditions studied. Fertilizer treatment did not affect thenumberof nodal buds, but we observed a higher apical dominance ratio and advanced bud burst in fertilized seedlings. In conclusion, nutrient availability influenced growth and bud phenology of understory Norway spruce seedlings at least down to 20 per cent DIFR.
Sammendrag
Feeding by pine weevil (Hylobius abietis L.) causes severe damage to newly planted conifer seedlings in most parts of Scandinavia. We investigated the effect of planting time and insecticide treatment on pine weevil damage and seedling growth. The main objective was to study if planting in early autumn on fresh clear-cuts would promote seedling establishment and reduce the amount of damage caused by pine weevil the following season. The experiment was conducted in southern Sweden and in south-eastern Norway with an identical experimental design at three sites in each country. On each site, Norway spruce seedlings with or without insecticide treatment were planted at four different planting times: August, September, November and May the following year. In Sweden, the proportion of untreated seedlings that were killed by pine weevils was reduced when seedlings were planted at the earliest time (August/September) compared to late planting in November, or May the following year. This pattern was not found in Norway. The average length of leading shoot, diameter growth and biomass were clearly benefited by planting in August in both countries. Insecticide treatment decreased the number of seedlings killed or severely damaged in both Norway and Sweden.
Forfattere
Johannes BreidenbachSammendrag
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Sammendrag
Berry yield and chemical composition of four commercial black currant cultivars were recorded in a field experiment in Norway over an 8-year period and related by linear regression analysis to temperature and precipitation conditions prevailing during the May-July preharvest period. Highly significant differences between cultivars and among years were found for all measured parameters. Fruit dry matter, soluble solids and pH were positively correlated with temperature and negatively correlated with precipitation during May-July, while yield, berry weight, and the concentration of total phenols and ascorbic acid showed the opposite relationship, being highly negatively correlated with temperature and positively correlated with precipitation. Similar black currant experiments elsewhere in Europe have often given deviating results, varying from opposite to no effects of the same weather variables, suggesting that fruit composition is influenced by several interacting genetic and environmental parameters. We conclude that differences in local weather and soil conditions and the use of different cultivars complicate direct comparison of such field experiments. Nevertheless, the observed strong and opposite correlations with precipitation and temperature suggest an inherently low drought tolerance of black currant plants.