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.
2025
Abstract
European livestock sectors rely heavily on imported protein feeds, presenting challenges regarding sustainability and supply security. Green biorefineries (GBR) represent a local alternative where protein concentrates are extracted from grassland crops, but the environmental performance of these systems depends on feedstock cultivation practices. This study combined field trials and life cycle assessment (LCA) to quantify how nitrogen (N) fertilization rates, clover inclusion rates, and feedstock management (fresh vs. ensiled) affect dry matter (DM) and crude protein (CP) biomass yields, as well as subsequent climate impact, and agricultural land use of GBR products. The results reveal that N fertilization during cultivation of feedstock biomass plays a critical role in the climate impact of green biorefining, and that including legumes enhances GBR sustainability. Increasing N fertilization from 0 to 240 kg N ha−1 in red clover–grass swards increased DM and CP biomass yields but also increased soil N₂O emissions and upstream fertilizer burdens. Under no N fertilizer treatment, biological N fixation supported high yields, resulting in the lowest net climate footprint in the ensuing LCA of the GBR process. However, this treatment also required around 60 % more land than the high N treatment. Processing ensiled feedstock further reduced the climate impact compared to fresh biomass by retaining more CP in the liquid fraction and eliminating several biorefinery steps. However, this benefit in this case was linked to the use of the liquid phase rather than ensiling itself, and similar outcomes could be achieved with fresh biomass if processed accordingly and used immediately after production. Future work must expand system boundaries to include transport, storage, and animal-feeding stages, and develop farm-level strategies that align GBR practices with regional conditions.
Abstract
Nitrogen (N) management is one of the main factors enhancing potato productivity and promoting sustainable agricultural practices. The Nitrogen Nutrition Index (NNI, obtained as the ratio of actual plant N, to the critical plant N concentration) is widely applied to assess the N status of various crops. Traditionally, NNI is calculated using field data, but remote sensing (RS) technologies can offer more rapidly and timely assessment of the spatiotemporal (within field) variability of this index. This study employs multispectral data acquired via Unmanned Aerial Vehicle (UAV) and machine learning (ML) models to estimate potato NNI. A Bayesian hierarchical partially pooled method was fitted to a three-year f ield experiment in Denmark and extensive ground-based potato datasets to model the critical nitrogen dilution curve (CNDC) and calculate the NNI. Multispectral UAV data were processed to extract four spectral bands and calculate several vegetation indices, which were used as predictors to train and test six ML models: Linear regression, support vector machines, gaussian process regression, stepwise linear regression, ensemble trees and neural networks. Among the compared models, gaussian process regression outperformed, showing R 2 equal to 0.83 and a RMSE of 0.10 and providing accurate NNI predictions, comparable to ground-based Bayesian estimates. The variability of the NNI was analyzed over the seasons using 28 NNI maps derived from UAV surveys at spatial resolution of 0.04–0.09 m/pixel, capturing spatial variations in crop N status over time. The proposed framework, designed for NNI prediction at the intra-field scale, has the potential to be adapted to different environments and crops. The framework can support practical decisions for precision N management, reducing the environmental impact of potato cultivations and enhancing sustainability.
Authors
Elena Arrigoni Ruairi Hafferty-Hay Pino-Raquel Bodas Liv Guri Velle Kerry Bradshaw Zeren Yang Amanda Cooper Tim Wilkinson Jeffrey G. Duckett Silvia Pressel Rachael Howlett Justin Moat Susan Zappala Martin I. Bidartondo Laura M. Suz Jill KowalAbstract
Heathlands are among the most iconic habitats in Northern Europe, with 20% of the world’s total area in the UK. Their wide, open landscape is dominated by low-growing Ericaceae shrubs and associated ericoid mycorrhizal (ErM) fungi on nutrient poor, acidic, dry or waterlogged, organic soils. ErM fungi enable N and phosphorus uptake by their plant hosts in exchange for carbon, playing a crucial role in nutrient cycling and contributing to carbon stocks. These fungi also form intimate associations with the rhizoids of several leafy liverworts, including the widespread heathland liverwort Cephaloziella divaricata. In the 20th Century, nitrogen (N) pollution alongside urbanisation and tree encroachment, have severely impacted heathlands, contributing to their sharp decline. The effects of N pollution on heathland vegetation are well documented, with useful indicators including lichens and bryophytes. However, little is known about how the soil microbiome, including mycorrhizal-forming fungi, is impacted by N pollution. Also lacking is understanding of how heathland might recover; with N pollution now declining across parts of Europe, there is demand from managers and policymakers for novel indicators of heathland recovery. Our research investigates responses of ErM fungi to, and recovery from N pollution, and evaluates their suitability as recovery indicators. 18In 2021, we reinstated a dormant experiment in a dry heathland at Thursley National Nature Reserve (Surrey, UK) where N additions ceased in 2010. Results showed lingering effects of N additions on heather vegetation, moss ground cover, lichen communities, soil chemistry and soil fungal communities, while a negative trend was observed in root ErM colonisation in N-treated plots. In 2023, we established thirty new plots, 15 fertilised with 30 kg/ha of ammonium nitrate (NH4NO3), and 15 as controls. To account for plant age, 20 plots were located within mature C. vulgaris stands, and 10 on pioneer vegetation (wildfires occurred in 2006 and 2020, respectively). Combining eDNA techniques and microscopy, we are monitoring ErM root and rhizoid colonisation in C. vulgaris and C. divaricata respectfully, diversity of fungal communities in roots and soil, and soil fungal biomass. A lichen survey was conducted to assess differences in postfire recovery. Vegetation structure and biomass changes are monitored with LiDAR, RGB and multispectral drone imaging to develop a complementary carbon calculation method. We also sampled six coastal heathlands in Norway, along a south-north N deposition gradient (1-6 kg N/ha/yr), and a comparable wet heathland at Thursley (13 kg N/ha/yr) to investigate potential mycorrhizal indicators of healthy heathlands below the N critical load. Preliminary results show ErM fungi are more diverse than expected, with ongoing analyses linking root colonisation to N deposition and climate data to understand heathland recovery and identify potential nitrophilic and nitrophobic ErM fungi as recovery indicators.
Abstract
In this article we show benefits of quota flexibility in a single-stock fishery model where one of the firms is allowed to behave strategically in the trading of quotas while other firms in the fishery are price takers. The ex-vessel price for fish is assumed constant. Quota flexibility is implemented through a settlement at the end of each regulation period. In that settlement firms having unused quotas are compensated by a subsidy, while those who have quota shortfalls are obligated to pay a tax. For the same deviation the tax is higher than the reward. Former literature shows that market power under a traditional ITQ system can lead to inefficiencies. However, losses due to market power can be subdued when quotas are more flexible. A simple argument to account for this view is that the competitive fringe of firms in the flexible case have the option to make use of the tax/reward system. Thus, rather than being exploited by the price manipulating firm the competitive fringe might find it better to deviate from the 1:1 “quota — realized catches”- relationship that characterizes competitive equilibrium.
Abstract
In this article we show benefits of quota flexibility in a single-stock fishery model where one of the firms is allowed to behave strategically in the trading of quotas while other firms in the fishery are price takers. The ex-vessel price for fish is assumed constant. Quota flexibility is implemented through a settlement at the end of each regulation period. In that settlement firms having unused quotas are compensated by a subsidy, while those who have quota shortfalls are obligated to pay a tax. For the same deviation the tax is higher than the reward. Former literature shows that market power under a traditional ITQ system can lead to inefficiencies. However, losses due to market power can be subdued when quotas are more flexible. A simple argument to account for this view is that the competitive fringe of firms in the flexible case have the option to make use of the tax/reward system. Thus, rather than being exploited by the price manipulating firm the competitive fringe might find it better to deviate from the 1:1 “quota — realized catches”- relationship that characterizes competitive equilibrium.
Authors
Lampros LamprinakisAbstract
No abstract has been registered
Authors
Jørgen A.B. MølmannAbstract
Potato with origins from temperate/alpine regions of South America is well suited for agricultural production in the cool climates at high latitudes in Greenland, Iceland, Faroe Islands and northern Fennoscandia. Here, the importance of potato as a staple crop is likely to increase in the future due to global warming. Potentially contributing to a larger share in food production from the north. As well as providing local food security under the risks of unstable geopolitics or natural disasters. Earlier snowmelt and ground thaw extending the growth season within the Midnight Sun period, and a larger accumulated degree day sum is likely to improve production at high latitudes. We have studied the influence of temperature on the minimum light requirement for potato growth under Arctic day lengths. Our results show that the radiation required for high yields increases as temperatures decrease below the optimum for tuber growth. On the other hand, at increasing temperatures the requirement for high irradiance decreases. This means that potato plants may utilize the very long daily photosynthesis periods more efficiently under warmer temperatures at high latitudes in the future. Thus, resulting in potential higher yields and increased profitability for northern potato producers. The latter may counteract some of the current logistical challenges for the potato industry in the high north. This together with agricultural policies centered on self-sufficiency can give cause for optimism among potato producers at high latitudes.
Authors
Jørgen A.B. MølmannAbstract
Omvisning med orientering om potetforsøk ved BIologisk klimalaboratorium i Tromsø
Abstract
The 2025 update of the Norwegian Red List shows that coastal heathlands remain threatened. Key ongoing threats include abandonment of traditional land use and development of the areas. Recently compiled statistics from habitat mapping provide insights into the ecological condition of the heathlands. The data reveal that more than half of the remaining coastal heathland areas lack active management, putting them at risk of encroachment in the coming years. Moreover, data show that the proportion of areas in the late successional phase is surprisingly low, just over ten percent, despite widespread degradation due to encroachment. This suggests that degraded coastal heathlands are difficult to identify and are likely being misclassified as other habitat types, such as forest. To help field surveyors avoid misidentification, a map illustrating the potential distribution of coastal heathlands in Norway has been developed, along with clear inclusion and exclusion principles. The map extends the previously known northern range of heathlands and reaches south eastward toward heathland areas in Sweden. Norway currently lacks representative monitoring of coastal heathland, as existing programs miss rare habitats. It is therefore a welcome step that the Norwegian Environment Agency now proposes the development of a dedicated monitoring program.
Abstract
Due to the economic importance of protected strawberry production and its relatively high environmental impact, more sustainable cultivation methods are needed. This study compared alternative growing media effects on plant growth and berry production. 'Sonsation' strawberries were grown in six substrates: 100% peat, 100% wood fibre, 50% peat/50% wood fibre (with and without fertilizer), and two compost and wood fiber-based products ('Nittedal' peat-free and '29 mod' peat-reduced). Irrigation treatments included standard fertigation and pure water (for 'Nittedal' and '29 mod'). In the first five weeks, the tallest (35 cm) and shortest (30 cm) plants were recorded in '29 mod' and 'Nittedal' grown on pure water, respectively. The other treatments showed consistent plant height between 33–35 cm. While peat-based media resulted in the highest yield, alternative materials performed similarly, except for a lower yield in the peat-free 'Nittedal' with pure water, with no added fertilizer. This treatment also had fewer inflorescences per plant and lower biomass production. In addition, pH and electrical conductivity measurements indicated that peat-reduced and peat-free substrates maintained optimal pH levels for strawberry growth (between 5.5-6.5). Overall, while peat-based media produced the best-performing plants, the more sustainable alternatives demonstrated comparable performance, making them viable options for strawberry cultivation.