Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2007
Sammendrag
The objective of this study was to examine the effect of clover species on milk fatty acid (FA) composition. Lactating dairy cows were allocated to two groups and fed grass-clover silage containing either white clover (WC) or red clover (RC), without or with concentrate supplementation. No significant interaction of clover species with concentrate supplementation could be observed. RC milk had significantly higher proportion of polyunsaturated FAs (P<0.001), particularly C18:3n-3 (P<0.001), and contained a higher n-3/n-6 FA ratio (P<0.05) than WC milk. It is concluded that RC silage, independent of concentrate supply, yielded milk with more beneficial FA composition than WC silage.
Forfattere
Trine A Sogn Espen Govasmark Susanne Eich-Greatorex Anne Falk Øgaard John A. MacLeodSammendrag
In some parts of the world, the soil selenium (Se) content is too low to ensure the Se level recommended for human or animal consumption in the crops produced. In order to secure a desired concentration of Se in crops, Se has been applied as mineral fertilizer to agricultural fields. Since only a minor part of the inorganic Se applied is utilized by plants and small increases in Se concentrations in, e.g., drinking water, may be toxic, the method is somewhat controversial. As an alternative to Se-enriched mineral fertilizer, different seafood-processing wastes have been examined as a source for Se in crop production. Both in greenhouse pot experiments and field trials the Se in seafood waste was not plant-available during the first growing season. There was no significant difference between the Se concentration in wheat growing in soil without added Se and in soil receiving Se from seafood waste in amounts ranging from 0.9 to 9 g ha(-1). Neither was any residual effect of Se in seafood waste seen during a second year growth period. Thus, seafood-processing waste cannot be regarded as a potential source of Se in crop production. Possible mobilization of formerly applied Se, as seafood-processing waste or Se enriched mineral fertilizer due to changes in soil redox conditions were examined in a leaching experiment. The mobility of formerly applied Se was generally very low, but the results indicated that under permanently wet soil conditions leaching of Se may occur in plant dormant periods in soils with low organic matter content and high pH.
Sammendrag
City planners need practical methods to assess and compare the sustainability of different alternatives for urban infrastructure. This article presents the consequences of selecting different methods to normalize the values of sustainability indicators, and the influence of selecting different indicators and different weighting techniques. A nature based sewerage system is compared to a conventional system. The article demonstrates that the method used to normalize the indicators, the choice of relevant indicators and the weighting technique have considerable influence on which system is found to be the most sustainable. By selecting particular indicators, weighting and normalization methods, it is possible to prove that virtually any infrastructure system is more sustainable than any other alternative system. Such a biased approach is difficult to reveal unless the most careful, expert scrutiny is applied. Because of this fact, it is of paramount importance that the consequences of different evaluation methods are discussed and sensitivity analyses are carried out honestly and objectively on the critical parameters. An evaluation process made in this way will enable those parts of the analysis that generate disagreement to be identified, and decisions taken on what is important and unimportant.
Forfattere
Hege Hvattum Divon Robert FluhrSammendrag
In host-pathogen interactions, efficient pathogen nutrition is a prerequisite for successful colonization and fungal fitness. Filamentous fungi have a remarkable capability to adapt and exploit the external nutrient environment. For phytopathogenic fungi, this asset has developed within the context of host physiology and metabolism. The understanding of nutrient acquisition and pathogen primary metabolism is of great importance in the development of novel disease control strategies. In this review, we discuss the current knowledge on how plant nutrient supplies are utilized by phytopathogenic fungi, and how these activities are controlled. The generation and use of auxotrophic mutants have been elemental to the determination of essential and nonessential nutrient compounds from the plant. Considerable evidence indicates that pathogen entrainment of host metabolism is a widespread phenomenon and can be accomplished by rerouting of the plant's responses. Crucial fungal signalling components for nutrient-sensing pathways as well as their developmental dependency have now been identified, and were shown to operate in a coordinate cross-talk fashion that ensures proper nutrition-related behaviour during the infection process.
Forfattere
Kinga Adam Tore Krogstad Lasse Vråle Anne Kristine Søvik Petter D. JenssenSammendrag
Filtralite P (R) and shellsand as ideal constructed wetland substrates have been tested for their P sorption capacity, both with batch and column experiments. Two columns were filled with Filtralite PI and one column with shellsand. The shellsand (SSPS) and one of the Filtralite P (R) columns (FLSP) were loaded with a synthetic P solution, while the second Filtralite P (R) column (FLWW) was loaded with secondary wastewater. Ca, Mg, pH, and the P concentrations were measured in the inlet and the seven outlets along the height of the three vertical upflow columns for up to 303 days. An overall P removal rate of 92, 91, and 54% was measured in the columns SSPS, FLWW, and FLPS, respectively, for the entire experimental period. The comparison of FLWW and FLPS showed that FLWW kept its high P removal efficiency (91%) throughout the experimental period while the removal efficiency of FLPS decreased fast after reaching the 1 ppm effluent P concentration. The competition of other negative ions and the development of biofilm did not have a negative effect on P removal from wastewater. The batch experiments showed a better sorption capacity of Filtralite P (R) at low initial concentrations, while for high initial concentrations the shellsand sorbed more. Shellsand had, however, a higher sorption capacity in batch experiments with used column material and high initial P concentrations. The results from both the batch and the column experiment suggest that the shellsand has a more durable P sorption capacity than the Filtralite P (R) material, possibly due to the persistent high concentrations of Ca in the shellsand. (c) 2006 Elsevier B.V. All rights reserved.
Sammendrag
No abstract has been registered
Forfattere
Hege Nordheim-Viken Harald Volden Gustav Fystro Tor LunnanSammendrag
No abstract has been registered
Forfattere
Ievina Sturite Trond Maukon Henriksen Tor Arvid BrelandSammendrag
Conclusions The short lifespan and poor over-wintering of leaves showed their potential importance as a nitrogen source in the soil-plant ecosystem but also their potential contribution to the risk of off-season N losses.
Forfattere
Ievina Sturite Trond Maukon Henriksen Tor Arvid BrelandSammendrag
We have studied to what degree Italian ryegrass (Lolium multiflorum Lam.), white clover (Trifolium repens L.) and meadow fescue (Festuca pratensis L.) are able to preserve nitrogen (N) and phosphorous (P) in shoots and roots from one growing season to the next in a northern temperate climate. Field experiments were performed during four consecutive winters in central southeast Norway (60 degrees 42'N, 10 degrees 51'E), and N and P in plant biomass were measured in the autumn and in the spring. We also measured the contents of total N, total P and organic carbon (C) in seepage water that percolated through the aboveground plant material. Uptake of N and P in Italian ryegrass and white clover was substantially larger than in meadow fescue. The winter losses varied greatly from year to year, depending on the winter climate. On the average for all three of the plant species, the winter losses of N from aboveground biomass were 6, 35, 68 and 10% in the four experimental years, respectively. The corresponding P losses were 11, 36, 60 and 22%. On the average for all plant species and experimental years, 43 (+/- 12)% (S.E., n = 12) of the N, 34 (+/- 9)% of the P and 4 (+/- 1)% of the C that was lost from the aboveground plant biomass during the winter, was recovered in seepage water, basically as a nutrient pulse in melt water in early spring. The very low C recovery rate in seepage water suggested a considerable microbial growth on lost plant C. Assuming that all un-recovered plant C was consumed by microorganisms not included in measurements of the seepage water, modelling showed that microbial immobilisation theoretically might explain the unexpectedly low recovery rates of N and P. The study was not designed to investigate the possible effects of psychrophilic microbes on N and P cycling. Therefore, it is inconclusive and underlines the need for more knowledge on this matter. (c) 2006 Elsevier B.V. All rights reserved.
Forfattere
Nicholas Clarke Yijie Wu Line Tau StrandSammendrag
Boreal forests are increasing in age partly due to reduced logging and efficient wildfire control. As a result, they also stock more carbon. Whether increased forest C stock causes greater production of dissolved organic carbon (DOC) is uncertain. DOC in bulk precipitation, throughfall and soil water was studied in 10-, 30-, 60- and 120-year-old stands of Norway spruce (Picea abies (L.) Karst.) DOC concentrations in throughfall and O horizon soil water followed the order 10<30<60 = 120 and 10 = 30<120<60, respectively. DOC fluxes followed the order 10 = 30<60 = 120 in throughfall, while no significant difference between stands was found for O horizon soil water. Above-ground tree litter varied according to 10<30<60 = 120, a pattern identical to that for DOC concentrations in throughfall and resembling but not identical to that for DOC concentrations in O horizon soil water. This indicates additional sources for DOC in soil water. Seasonality in DOC concentrations was observed at the base of the O horizon, and seasonality in DOC fluxes in both throughfall and O horizon soil water. Our results suggest differences in the polarity of DOC between the 10-year stand and the others, which we interpret as reflecting the lack of grown trees and possibly the different vegetation on the 10-year stand.