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.
2018
Forfattere
John Koestel Annette Dathe Todd H. Skaggs Ove Mindor Klakegg Muhammad Arslan Ahmad Maryia Babko Daniel Giménez Csilla Farkas Attila Nemes Nicholas JarvisSammendrag
The saturated hydraulic conductivity of soil, Ks, is a critical parameter in hydrological models that remains notoriously difficult to predict. In this study, we test the capability of a model based on percolation theory and critical path analysis to estimate Ks measured on 95 undisturbed soil cores collected from contrasting soil types. One parameter (the pore geometry factor) was derived by model fitting, while the remaining two parameters (the critical pore diameter, dc, and the effective porosity) were derived from X‐ray computed tomography measurements. The model gave a highly significant fit to the Ks measurements (p < 0.0001) although only ~47% of the variation was explained and the fitted pore geometry factor was approximately 1 to 2 orders of magnitude larger than various theoretical values obtained for idealized porous media and pore network models. Apart from assumptions in the model that might not hold in reality, this could also be attributed to experimental error induced by, for example, air entrapment and changes in the soil pore structure occurring during sample presaturation and the measurement of Ks. Variation in the critical pore diameter, dc, was the dominant source of variation in Ks, which suggests that dc is a suitable length scale for predicting soil permeability. Thus, from the point of view of pedotransfer functions, it could be worthwhile to direct future research toward exploring the correlations of dc with basic soil properties and site attributes.
Sammendrag
It is recognised that flame retardant chemicals degrade and leach out of flame-protected wood claddings when exposed to natural weathering. However, the ability to survey the current state of a flame retardant treatment applied to a wood cladding, an arbitrary length of time after the initial application, is limited today. In this study, hyperspectral imaging in the near infrared to short-wavelength infrared region is used to quantify the amount of flame retardant present on wooden surfaces. Several sets of samples were treated with various concentrations of a flame retardant chemical and scanned with a push broom hyperspectral camera. An inductively coupled plasma (ICP) spectroscopy analysis of the outermost layer of the treated samples was then carried out in order to determine each sample’s phosphorus content, the active ingredient in the flame retardant. Spectra from the hyperspectral images were pre-processed with extended multiplicative scatter correction, and the phosphorus content was modelled using a partial least squares (PLS) regression model. The PLS regression yielded robust predictions of surface phosphorus content with a coefficient of determination, R2, between 0.8 and 0.9 on validation data regardless of whether the flame retardant chemical had been applied to the surface of the wood or pressure-impregnated into it. The result from the study indicates that spectral imaging around the 2400–2531nm wavelength region is favourable for quantifying the amount of phosphorus-based flame retardant contained in the outermost layer of non-coated wooden claddings. The results also reveal that the uptake of phosphorus-based flame retardant does not occur uniformly throughout the wood surface, but is to a larger extent concentrated in the earlywood regions than in the latewood.
Forfattere
Anne Kjersti BakkenSammendrag
Det er ikke registrert sammendrag
Forfattere
Lars T. HavstadSammendrag
Det er ikke registrert sammendrag
Sammendrag
En rekke forhold har betydning for en vellykket etablering av oljevekster; jordart, jordarbeiding, frøkvalitet, sådybde, såmengde, tilgang til næring, temperatur og nedbør etter såing og angrep av skadedyr.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Knut ØistadSammendrag
Det er ikke registrert sammendrag
Forfattere
Pablo Velasco N Abdlmotalb M Tortosa C Mollers A Ciruelos A de Haro Tor J. Johansen A McAlvay C Pires VM RodríguezSammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Trygve S. Aamlid Oiva Niemelainen Klaus Paaske David Widmark Pentti Ruuttunen Auli KedonperaSammendrag
Greenkeepers are looking for alternatives to fungicides for control of turfgrass diseases. Our objective was to evaluate a petroleum- derived spray oil with a blue-green pigment for control of Microdochium patch/pink snow mold (Microdochium nivale) on golf course putting greens with various durations of snow cover. The spray oil was applied at rates 27 or 54 L ha–1 every third week from late August or September to December, either alone, in tank mixture with potassium phosphite (3 kg PO3 ha–1) or in tank mixture with half rate of fungicides approved for turf, in five 1-yr trials in the Nordic countries. The oil was as effective or more effective than fungicides and gave, on average, 94 and 98% disease control at rates 27 and 54 L ha–1, respectively. Tank mixtures with half rate of prochloraz + propioconazole and fludioxonil did not increase disease suppression in a trial with 79 d snow cover. Phosphite reduced disease severity in one trial only and did not improve disease control or turfgrass quality when tank-mixed with the oil. The pigment in the spray oil was highly persistent and improved turfgrass greenness except in a trial where the combination of oil and ice cover gave a transitory black color at ice melt. Another trial with long snow cover showed a drop in turfgrass quality in spring as the spray oil prevented normal green-up. In conclusion, this research shows that a spray oil has the potential to reduce fungicide use on Nordic golf courses.