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
Presenting the status and results of the nitrate transport modelling for the Želivka (Czech Republic) and Himmerland (Denmark) catchments using the SWAT+ model
Abstract
SWAT+ modelling and scenario results for changes in nitrate leaching to shallow groundwater in the Himmerland catchment, Denmark, with afforestation, set aside and fertilization reduction. Results are calculated for present and future climate conditions.
Authors
Berhanu Menasbo Tegegne Emiru Birhane Fasil Eregno Ståle Haaland Samuel Alemayehu Tesfamariam Teklu Gebretsadik Abraha Gebrekidan AsgedomAbstract
Capping is an effective method for reducing internal nutrient loading in eutrophic water bodies, but research on low-cost materials, especially for trapping nitrogen and phosphorus, remains limited. This study evaluates the performance of a dual-layer biochar and zeolite capping system in mitigating nutrient fluxes. The structural and compositional properties of the materials were characterized using advanced techniques such as scanning electron microscopy, electron diffraction spectroscopy, and Raman spectroscopy. Three setups at 16 C and 24 C were tested for 60 d: (1) uncapped sediment, (2) nonwoven fabric mat (NWFM) with zeolite over biochar, and (3) NWFM with biochar over zeolite. Both capping configurations significantly reduced ammonium-nitrogen flux. The zeolite-on-top setup achieved the lowest total nitrogen flux at 16 C (1.03 mg/m2/d), while uncapped sediment had the highest at 24 C (5.02 ± 1.36 mg/m2/d). Zeolite at the top layer enhanced nutrient retention—up to 95% ammonium and 98% phosphorus—while maintaining dissolved oxygen and reducing chemical oxygen demand. These results highlight the short-term efficacy of dual-layer capping as a cost-effective approach for lake restoration. Further field-scale studies are recommended to assess long-term outcomes.
Abstract
A survey was conducted in Porsangmoen-Halkavarre shooting and training range. This report summarizes the results of exploratory fishing and extensive environmental surveys carried out in 2024 in five lakes: Store Ikkasvann (Stuorra Inggasjávri), Lille Ikkasvann (Unna Inggasjávri), almijervi (Coalbmejávri), Lille Russevann (Bajit Russojávri) and Store Russevann (Stuorra Russojávri), as well as in Ørretbekken, an important spawning stream for the trout (Salmo trutta) population in Store Ikkasvann (Stuorra Inggasjávri). The study includes catch-per-unit-effort (CPUE, species distribution, growth and biometrics), water chemical and physical analyses, sediment studies, as well as observations of macrophytes and habitat conditions. The aim was to document variations in fish communities and ecological status, and to identify possible environmental challenges that may affect future management and conservation of the resources in the area. The findings show that trout predominate in the shallow areas (0–6 m deep) of Store Ikkasvann (Stuorra Inggasjávri) and Lille Ikkasvann (Unna Inggasjávri), while char (Salvelinus alpinus) is more abundant in the deeper water layers. In Salmijervi (Coalbmejávri), the species distribution is more balanced, while Store Russevann (Stuorra Russojávri) and Lille Russevann (Bajit Russojávri) are characterized by a higher density of char. Minnow (Phoxinus phoxinus) was found in three of the lakes, especially in shallow areas, which can affect traut grawth thraugh competition and predation. Biometric analyses indicate that traut graw fastest in Lille Russevann (Bajit Russojåvri) (with 5.1 cm annual grawth) and slowest in Salmijervi (Coalbmejåvri) (4.3 cm), while char maintains a steady growth of about 5 cm per year. Colour differences in fish meat·suggest that a high percentage of traut from Store Russevann (Stuorra Russojåvri) and Lille Russevann (Bajit Russojåvri), and both traut and char from Store Ikkasvann (Stuorra Inggasjåvri) and Lille Ikkasvann (Unna Inggasjåvri) have a more reddish color, possibly due to a higher intake of crustaceans. The parasite occurrence in traut and char was generally low, except for fish in Salmijervi (Coalbmejåvri), where increased bird activity may have led to higher infection rates. Water chemistry measurements showed that most water bodies have good water quality with low concentrations of lead, same copper and zinc, relatively low nutrient concentrations, a high con tent of calcium carbonate and thus stable pH values (7-8). At the same time, the analyses oflake sediments indicate good condition for lead (which is an EU priority substance), but occasionally poor to very poor status for copper and chramium, as well as high concentrations of nickel. Nickel, copper and chramium occur naturally in minerals in the catchment area. A mapping of bioaccumulation of heavy metals could be done to get an idea of base line concentrations in fish in the area. Observations of heteratraphic grawth increasing down the watercourse, possibly associated with sewage discharges or other organic loads, underscore the need for DNA-based source tracing to precisely define the sources of pollution. The traut stream, which maintains high densities of traut and is in very good ecological condition, must be managed with special consideration, where raad construction and other activities must be thoraughly assessed with risk analyses, strict mass management and sediment control. Overall, the report shows that the ecological water quality is good to very good, and fish stocks in most of the lakes have good spawning and grawth conditions, with same regional differences related to habitat use and grawth conditions. The management should adopt a holistic, catchment-oriented approach to new interventions in the area, with a fous on minimising the impact on water bodies and ensuring sustainable use of resources. More detailed suggestions are mentioned in the report, which forms a basis for further monitoring and enviranmental measures to preserve biodiversity and , maintain the good ecological status of the entire area.
Abstract
No abstract has been registered
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Abstract
Nature-based solutions (NBS) have been broadly adopted to strengthen water and wastewater sanitation by effectively removing microbial pollutants and limiting significant health risks to aquatic environments and humans. However, temporal variations of pathogen removal efficiencies in NBS and the specific link with faecal pollutants remain understudied. In this study, a Norwegian urban NBS operating as a nature-based treatment system (NBTS) for water purification was monitored on pathogen removal capacities and faecal source tracking through a 1-year study. Applying coupled molecular analyses, i.e., pathogen molecular detection and genetic microbial source tracking, enabled the systemic assessment of this NBTS’s remediation performance while unveiling the intrinsic link between pathogen prevalence and the faecal pollution sources. Notably, the system exhibited stronger pathogen attenuation activity on Enterococcus faecalis, Salmonella enterica serovar Typhimurium, Clostridium perfringens, and Legionella pneumophila (linked closely to human origin in the studied NBTS) than Shigella species and Giardia lamblia sourced mainly from animals. Moreover, the studied system displayed temporal dynamics of its functioning. As such, more fluctuations often occurred in cold months than in the warm period and under varying impacts of measured environmental conditions (i.e., water temperature, pH, electrical conductivity, dissolved oxygen, total dissolved solids, salinity, and oxidation reduction potential). Collectively, the findings of this study consolidate the functional potential of NBS in combating the microbial pollution that results specifically from waterborne enteric pathogens in a tight link with faecal contamination. The disclosed performance seasonality also calls for extra consideration for better-informed system management and remediation enhancement. Last but not least, the holistic study outcomes underscored the explicit value of applying complementary molecular approaches to achieve deeper insights into the functional status of a target NBS over time.
Abstract
Purpose: Rice production in paddy soil is important for food security, and nitrogen fertilisation is important to achieve high yields. Digestate, the organic rest from biogas production can be a good fertilizer, but relatively little is known about its use in paddy soil, which is investigated here. Method: Nitrogen transformations and rice growth in soil waterlogged and at field capacity after application of digestate and digestate products were assessed in a pot experiment. Nitrogen transformations and nitrous oxide (N2O) emissions with the same digestates were also assessed in an incubation. Results: One of the tested digestates had as good fertilizer effect as urea. Nitrogen transformations went mostly as expected under given water status, but digestates were more affected by waterlogging than urea. Some instability appeared about 10 days after fertilizer application. Then nitrite levels were high, responsive microbial populations peaked and N2O emissions started. Whilst emissions after mineral fertilizer application (urea) were not affected by waterlogging, emission after application of one of the examined digestate was high at field capacity but almost zero under waterlogging. N2O emissions from all other digestate and water treatments were also low. Conclusion: Digestates have great potential as organic fertilizers in rice production, but N2O emissions under aerobic soil conditions are of concern and warrants further investigation and mitigation strategy.
Abstract
Research Highlights The microbial community applied with the digestate accelerated methane formation. CO2 emission was higher under waterlogging than at field capacity in soil with low organic content. Waterlogging decreased methane emission in unamended soil. Only digestate where some methane potential was left induced high methane emission. Methanogens and methanotrophs abundances dynamics partly explain emission patterns.
Abstract
Soil bulk density (BD) is a macroscopic indicator frequently used to infer the soils’ pore system, a fundamental attribute of terrestrial environments that significantly affects processes such as infiltration, water retention and plant root development. Additionally, BD is essential for assessing the storage of various materials in soils and sediments, including carbon and nutrients. High bulk density, often a consequence of soil compaction, represents a form of soil degradation that diminishes the soil’s functional capacity. Therefore, effective management of soil BD is crucial for improving agricultural yields, safeguarding ecosystem services, preventing degradation, and preserving the overall integrity of the Earth’s system. This review synthesizes recent research on the packing behavior of granular materials to clarify the emergent property of soil BD. The findings yield an empirical model that links packing fraction to the shape and size ratio of particles. The results demonstrate that the model accurately captures the frequently observed exponential decrease in soil BD with increasing soil organic matter (SOM) content. While it is widely recognized that particle density influences BD, the analysis indicates that grain shape exerts a considerable effect, followed by the particle size ratio in granular media. The insights from this study aim to transform the perception of BD from a static notion to one that acknowledges how changes in the morphology of soil constituents, driven by factors such as root growth and decomposition, can result in variations in BD. As a result, BD may become increasingly sensitive to feedback from climate and land use changes as the geometry of SOM evolves.