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
Forfattere
Johannes BreidenbachSammendrag
Det er ikke registrert sammendrag
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.
Sammendrag
Effects of three different pasture allocation techniques on milk yield and quality with mid-lactation dairy cows
Sammendrag
We assessed milk production with 24 mid-lactation Norwegian Red dairy cows on a spring pasture dominated by timothy (Phleum pratense) for a period of 21 days using three pasture allocation techniques (n=8). Cows received weekly allowances at once (7 day-set-paddocking; 7SP), grazed 1/7 of 7SP allowance each day (daily-strip-grazing; 1SG), or grazed like 1SG but also had access to the previously grazed part of the paddock (daily-forward-grazing; 1FG). We hypothesized that 7SP would deteriorate sward quality and quantity over the grazing days whilst the other two treatments would provide balanced pasture quality and intake. These changes were expected to result in differences in milk yield and its components. However, changes in sward chemical composition (e.g. neutral netergent fiber, crude protein) over the grazing days in each week were not different among treatments (treatment × grazing day; P>0.05). Furthermore, no effect of treatments on milk yield and its components was observed. Nonetheless, the effects of grazing days over a week on milk yield and components were different among treatments (treatment × grazing day; P<0.05). These treatment by grazing day interaction effects, in the absence main effect of treatment, could be due to fluctuations in daily DMI among treatments over the grazing days in each week.
Sammendrag
We assessed milk production with 24 mid-lactation Norwegian Red dairy cows on a spring pasture dominated by timothy (Phleum pratense) for a period of 21 days using three pasture allocation techniques (n=8). Cows received weekly allowances at once (7 day-set-paddocking; 7SP), grazed 1/7 of 7SP allowance each day (daily-strip-grazing; 1SG), or grazed like 1SG but also had access to the previously grazed part of the paddock (daily-forward-grazing; 1FG). We hypothesized that 7SP would deteriorate sward quality and quantity over the grazing days whilst the other two treatments would provide balanced pasture quality and intake. These changes were expected to result in differences in milk yield and its components. However, changes in sward chemical composition (e.g. neutral netergent fiber, crude protein) over the grazing days in each week were not different among treatments (treatment × grazing day; P>0.05). Furthermore, no effect of treatments on milk yield and its components was observed. Nonetheless, the effects of grazing days over a week on milk yield and components were different among treatments (treatment × grazing day; P<0.05). These treatment by grazing day interaction effects, in the absence main effect of treatment, could be due to fluctuations in daily DMI among treatments over the grazing days in each week.
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
A future wetter climate in Northern Europe may increase soil compaction from traffic of heavy machinery. This study investigated the impact of tractor traffic on grassland yield, soil physical properties and penetration resistance in three experimental field trials in Norway; on medium sand at Tjøtta, Nordland, on silty medium sand at Fureneset, Sogn og Fjordane and on silt at Løken, Oppland. The experiments were conducted in a split-plot design with three levels of two wheel-by-wheel passes with tractor traffic after each cut: no traffic, light tractor or heavy tractor on large plots, and three different seed mixtures on small plots. The yield reduction by tractor traffic was 26% at Løken, 4% at Fureneset and 1% at Tjøtta. There was a positive correlation between soil moisture content and yield reduction by traffic. Tractor traffic reduced pore volume and air capacity and increased bulk density, compaction degree and penetration resistance with the largest effect at Løken and the smallest at Tjøtta. There were no statistically significant differences in yield or soil physical properties between light and heavy tractor. The study shows that soil texture and soil moisture content are major factors explaining traffic effects on soil physical properties and grassland yield.
Forfattere
Håvard SteinshamnSammendrag
Det er ikke registrert sammendrag
Forfattere
Steffen AdlerSammendrag
Det er ikke registrert sammendrag
Forfattere
Lise GrøvaSammendrag
Det er ikke registrert sammendrag