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.
2020
Authors
Aina Lundon RussenesAbstract
No abstract has been registered
Abstract
Lystgassutslipp har blitt målt over to vekstsesonger i et feltforsøk i Trøndelag med gras gjødsla med stigende mengder nitrogen. Nedbør og temperatur varierte mye i de to åra. Lystgassutslippene var spesielt høye i perioder like etter vårgjødling og like etter gjødsling etter førsteslått dersom jordtemperaturen var over 10°C og jorda var godt fuktig. Avlingsmengden økte ikke i gjødslingsintervallet fra 24 til 32 kg N per daa og år, men lystgassutslippene økte betydelig i samme intervallet. I gjennomsnitt gikk 0,6% av tilført N tapt som lystgass i måleperioden, som ikke omfattet seinsommer, høst og vinter. I rapporten diskuteres om balansert gjødsling, seinere gjødsling og deltgjødsling kan være gode strategier for å minske risikoen for denitrifikasjon og store lystgassutslipp fra eng om våren. Resultatene gir ikke grunnlag for å si at den offisielle utslippsfaktoren for lystgass på 1% av tilført N, bør heves, men samtidig er ikke vinterperioden med, og risikofaktorer som kløverinnslag og bruk av husdyrgjødsel ble ikke dekt av forsøket.
Authors
Kerry O'Donnell Abdullah M. S. Al-Hatmi Takayuki Aoki Balázs Brankovics José F. Cano-Lira Jeffrey J. Coleman G. Sybren de Hoog Antonio Di Pietro Rasmus J. N. Frandsen David M. Geiser Connie F. C. Gibas Josep Guarro Hye-Seon Kim H. Corby Kistler Imane Laraba John F. Leslie Manuel S. López-Berges Erik Lysøe Jacques F. Meis Michel Monod Robert H. Proctor Martijn Rep Carmen Ruiz-Roldan Adnan Šišic Jason E. Stajich Emma T. Steenkamp Brett A. Summerell Theo A. J. van der Lee Anne D. van Diepeningen Paul E. Verweij Cees Waalwijk Todd J. Ward Brian L. Wickes Nathan P. Wiederhold Michael J. Wingfield Ning Zhang Sean X. ZhangAbstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
Heidi KnutsenAbstract
«Norwegian Agriculture – Status and Trends 2019» provides a brief overview of major aspects of agriculture in Norway and summarises some of the information that is annually published within the sector.
Authors
Grete StokstadAbstract
No abstract has been registered
Authors
Ståle Størdal Minh Thi Hong Dinh Erik Haugom Gudbrand LienAbstract
We employ the event study methodology and simple descriptive measures to examine the performance of the Norwegian stock market before and in the first three months after the implementation of the lockdown policy in March 2020. Most of the financial losses occurred before the lockdown decision was made. In general, price volatility has been higher since the lockdown compared to the prior period. The information technology sector has performed best in the post-lockdown period, whereas the energy and finance sectors have performed worst. However, the finance sector has had a significant recovery in the post-event period. Among the marketplaces, Oslo Axess performed best in the month following the lockdown and has also experienced less volatility than Oslo Børs. A noticeable finding is that companies with headquarters in Norway have rebounded far better than those with headquarters abroad in the post-lockdown period.
Authors
Tore SkrøppaAbstract
No abstract has been registered
Authors
Sandra Rojas-Botero Jairo Solorza-Bejarano Johannes Kollmann Leonardo H. TeixeiraAbstract
Degraded tropical forests that were converted into pastures dominated by exotic grasses are a challenge for restoration due to arrested succession. Nucleation is a suitable strategy to restore such abandoned pastures as it can overcome seed and site limitation, and would foster the recovery of structural, functional, and species diversity. To explore the outcomes of different nucleation techniques in terms of richness, functional diversity, resource offer, and species and trait composition during the first year after implementation in an abandoned pasture in the tropical Andes, we conducted a field experiment with four nucleation treatments established in 1-m2 subplots, i.e. natural regeneration (control), seed rain transfer, seed bank transfer, and pre-grown plant mats. Number of species, functional diversity, proportion of natives, flowering and fruiting were response variables of the nucleation treatments and time since restoration using linear mixed-effects models. Species and trait composition trajectories over time were depicted with NMDS. Species richness and functional diversity of understory vegetation increased over time and with nucleation, being significantly higher by the final survey. Seed bank transfer introduced most species to the area in comparison to natural regeneration. Functional diversity, proportion of native, flowering, and fruiting species changed with time albeit with no differences among treatments. Species and trait composition showed convergence over time, which stresses the strong influence of environmental filtering in early restoration of abandoned pastures. Although positive aspects of planting trees and shrubs cannot be neglected, we argue that the incorporation of (several) more sophisticated nucleation techniques is beneficial for restoration of tropical forests.
Authors
Melesse Eshetu Moges Arve Heistad Thorsten HeidornAbstract
The blackwater stream of domestic wastewater contains energy and the majority of nutrients that can contribute to a circular economy. Hygienically safe and odor-free nutrient solution produced from anaerobically treated source-separated blackwater through an integrated post-treatment unit can be used as a source of liquid fertilizer. However, the high water content in the liquid fertilizer represents a storage or transportation challenge when utilized on agricultural areas, which are often situated far from the urban areas. Integration of microalgae into treated source-separated blackwater (BW) has been shown to effectively assimilate and recover phosphorus (P) and nitrogen (N) in the form of green biomass to be used as slow release biofertilizer and hence close the nutrient loop. With this objective, a lab-scale flat panel photobioreactor was used to cultivate Chlorella sorokiniana strain NIVA CHL 176 in a chemostat mode of operation. The growth of C. sorokiniana on treated source-separated blackwater as a substrate was monitored by measuring dry biomass concentration at a dilution rate of 1.38 d−1, temperature of 37 °C and pH of 7. The results indicate that the N and P recovery rates of C. sorokiniana were 99 mg N L−1d−1 and 8 mg P L−1d−1 for 10% treated BW and reached 213 mg N L−1d−1 and 35 mg P L−1d−1, respectively when using 20% treated BW as a substrate. The corresponding biomass yield on light, N and P on the 20% treated BW substrate were 0.37 g (mol photon)−1, 9.1 g g−1 and 54.1 g g−1, respectively, and up to 99% of N and P were removed from the blackwater.