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.
2026
Sammendrag
Forest transpiration is often quantified by scaling up stem sap flow measured on a few trees within a stand. This procedure carries uncertainty related to the (ill)representativeness of the sampled trees for the entire stand, often comprising several thousand transpiring trees. Here, we explored the uncertainty reduction potential afforded by increasing the number of sampled trees within the stand – not by costly sap flow monitoring equipment – but by point dendrometers measuring sub-daily fluctuations in stem radii which partially correlate with xylem water movement (i.e., sap flow). Using measurements collected in a forest dominated by even-aged spruce trees over two growing seasons, we built an empirical model for estimating hourly sap flow from individual trees equipped with point dendrometers, then applied it to estimate the daily transpiration of the stand both with and without trees equipped with point dendrometers. We found that the expanded tree sample size reduced the uncertainty of the stand-level estimate by 31–37 %, suggesting that the benefit afforded by increasing the stand representativeness outweighed the cost of introducing modeling error. Given their relative simplicity and affordability, we encourage additional investigations into the use of point dendrometers for studying tree water relations and water consumption patterns of entire forested stands.
Forfattere
Dafni Foti Stephen Amiandamhen Eleni Voulgaridou Elias Voulgaridis Costas Passialis Stergios AdamopoulosSammendrag
This study investigated the incorporation of various waste materials including wastepaper, Tetra Pak, wood chips and scrap tire fluff into flue gas desulfurization (FGD) gypsum and cement mortar matrices to produce sustainable composite materials. Four distinct composite types based on the waste materials were developed and evaluated for selected properties including thermal and acoustic insulation. The proportion of the waste materials was varied between 10 and 40 vol% of the base matrix. The compressive strength of the filled gypsum composites was in the range of 4.17–10.39 N/mm² while the pure gypsum was 11.38 N/mm². The addition of the wastes in gypsum composites reduced compressive strength by about 10% for the best recipe and as large as 60% for the worst combination. However, the measured strength still exceeds the strength of typical gypsum wallboard with a compressive strength of about 3–4 N/mm² for whole-board crushing tests and it is much lower for point loads. The normal-incidence sound absorption coefficient indicated that the waste-filled samples absorbed around 80% of the incident sound energy between 2000 and 3000 Hz, comparable to some commercial acoustic foams. The results highlight the potential of utilising these waste-based composites in environmentally friendly construction applications. Depending on the waste type and matrix used, the results revealed trade-offs between multi-functional performance and sustainability benefits.
Sammendrag
Potato field management in Europe is already optimized for high production and tuber quality; however, numerous environmental challenges remain if the industry is to achieve “green economy” targets, such as less resources utilized, and less nitrate leached to the environment. Strategic co-scheduling irrigation and nitrogen (N) fertilization might increase resource use efficiency while minimizing reactive losses such as nitrate leaching. This study aimed to quantify the combined effect of irrigation and N fertilization on potato production, growth, and resource use efficiencies. A field experiment was conducted from 2017 to 2019 on a coarse sandy soil in Denmark, with a drought event occurring in 2018. Full (Ifull, maximized), deficit (Idef, 70–80 % of Ifull) and low irrigation treatments (Ilow, minimized amount to keep crop survival), each under full (Nfull, maximized) and variable (Nvar, variable amount according to the crops’ needs) N fertilization were applied. The analyses results show that Ilow limited potato growth under a drought-heat event; otherwise, potato growth was comparable between Ifull and Idef treatments, with 31–32 % higher irrigation efficiency (IE) under Idef than under Ifull. Nitrate leaching was variable and not significantly different among the treatments, being in general 9–13 % lower under Idef in absolute terms than under Ifull. Unexpectedly, outcomes from Nvar were statistically lower compared to those from Nfull. Radiation use efficiencies (RUEs) from Ilow and Nvar were significantly lower than from Ifull and Idef (14–19 %), and from Nfull (9–11 %). N use efficiencies (NUE) were comparable between N fertilization treatments but significantly different among different irrigation treatments. Overall, this study confirms that Idef is the best irrigation strategy. Future efforts should focus on developing improved approaches for detecting in-season crop N status and further quantifying N requirements, as well as promoting the co-scheduled management of irrigation and N fertilization. Remote sensing approaches have great potential to assist with this.
2025
Sammendrag
As the world’s largest producer of Atlantic salmon, Norway produces approximately 1.5 million tons salmon per year. Marine aquaculture sludge (feces and excess feed) represents a substantial sidestream from the aquaculture sector, which has traditionally been released at sea as most salmon production operates in open cages in the fjords. In 2022, 12 000 tons of phosphorous and 70 000 tons of nitrogen were released from salmon production in Norway, thus contributing to eutrophication of the sea environment and while also representing substantial nutrients loss. While anaerobic digestion of freshwater fish sludge has been studied to some extent, marine aquaculture sludge (MAS) as a potential substrate for biogas production remains largely underexplored. High saline and high sulfate substrates, such as MAS, are known to have pervasive effects on microbial community composition and can be inhibitory to methanogenic archaea. Continued advances in meta-omic approaches are increasing our understanding of microbial communities, key microbial divers and their metabolic mechanisms in a given environment. We explored the impact of MAS on continuous biogas process performance and microbial dynamics during gradually increased loading of MAS feedstock and finally through reducing hydraulic retention time (HRT). The anaerobic digestion experiments were conducted in lab-scale continuous biogas reactors, and the amount of MAS, blended with cow manure, was increased from 20% volume to 100%, at a HRT of 28d. At 100% MAS loading, organic loading rate was further increased, by reducing HTR, from 28 to 12d. The process functioned successfully during the whole experimental phase (400 days), with maximum salt concentration reaching 25 g/L (12 g/L Na+), substantially higher than reported inhibiting levels at ~8 g/L Na+. Biogas production increased when MAS was increased, and specific biogas production at 25 and 12 d HRT remained relatively constant, at ~450 mL biogas/g tCOD. Initial microbial community analysis revealed a decrease in microbial species diversity with increased MAS load, yet no MAS-specific species emerged as key drivers in the recovered microbial community. Interestingly, the most abundant methanogenic archaea were associated with acetoclastic and halotolerant Methanothrix and Methanosarcina. Through 16S rRNA gene sequencing and metaproteomics, our study aims to provide further insight into the microbial populations and key metabolic pathways when subjected to high salinity and reduced HRT. Our study explores key microbial mechanisms during anaerobic digestion and biogas production from the novel MAS substrate, paving way for sustainable energy solutions, linking marine byproducts to renewable energy generation.
Sammendrag
Norway is the world’s largest producer of Atlantic salmon with an annual 1.5 million tons. The aquaculture sector produces large amounts of fish sludge (feces and excess feed), which has traditionally been released at sea as most salmon production operates in open cages in the fjords. In 2022, 12k tons of phosphorous and 70k tons of nitrogen were released from salmon production in Norway (Sample, 2024), thus contributing to eutrophication of the sea environment while representing substantial loss of plant nutrients. Recently, a few completely land-based salmon production facilities have been established, and the associated sludge has gained increased focus as potential substrate for anaerobic digestion (AD). While AD of freshwater fish sludge has been researched to some extent, properties of marine fish sludge (MFS) as substrate for biogas production remains poorly characterized. High saline substrates, such as MFS, are known to have pervasive effects on microbial community composition and can be inhibitory for methanogenic archaea. Continued advances in meta-omic approaches increase understanding of microbial communities and their metabolic mechanisms in a given environment. Here, we investigated the impact of MFS on continuous biogas process performance and microbial dynamics during gradually increased volume loading of MFS feedstock. AD experiments were conducted in lab-scale continuous biogas reactors (CSTRs), and the amount of MFS (in mix with cow manure) was increased from 20% volume, to 100%, with stable process at hydraulic retention time (HRT) of 28d. When loading 100% MFS, organic loading rate (OLR) was increased (by reducing HRT), from 28 to 12d, representing increased OLR from ~4 to 10 g total organic demand (tCOD)/L/d. The process functioned during the total experimental phase (400 days), with maximum salt concentration at 25 g/L (12 g/L Na+), substantially higher than reported inhibiting levels at ~8 g/L Na+ (Zhang et.al., 2020). Biogas production increased from ~200 to 400 mL/g tCOD when MFS was increased. Specific biogas production at 25 and 12 d HRT remained relatively constant, at ~450 mL biogas/g tCOD, with stable methane concentration at ~65% throughout the experiment. Through meta-omic approaches (16S rRNA and whole genome sequencing), our study aims to provide insight into recovered microbial populations and key metabolic pathways when subjected to high salinity and increased OLR. Our study further aims to shed light on important microbial processes in AD running on novel substrates such as MFS, while paving way for sustainable energy solutions, linking marine byproducts to renewable energy generation. References Sample, J. E. (2024). Kildefordelte tilførsler av nitrogen og fosfor til norske kystområder i 2022–tabeller, figurer og kart. NIVA-rapport. Zhang, J., Zhang, R., He, Q., Ji, B., Wang, H., & Yang, K. (2020). Adaptation to salinity: Response of biogas production and microbial communities in anaerobic digestion of kitchen waste to salinity stress. Journal of bioscience and bioengineering, 130(2), 173-178.
Sammendrag
presentasjon seminar
Forfattere
Sartre, Liane MoniqueSammendrag
Integrated Pest Management (IPM) has been mandatory in Norway since 2015, as a strategy to reduce pesticide use and promote more sustainable agriculture. Studies show that implementation of IPM at farm level remains context-dependent, but so far no study on Norwegian fruit farming system had yet been conducted. This thesis aims to explore how Norwegian fruit farmers understand and apply IPM principles and what factors influence their adoption. A total of nine semi-structured interviews were conducted in two major fruit regions (Hardanger and Lier). The findings show that while several IPM principles are applied, especially preventive and non chemical methods, other principles are less implemented by farmers. IPM adoption is shaped by on-farm factors including technical constraints, infrastructures, economic concerns, social interactions, health and environmental awareness, as well as factors specific to the farmer. External influences such as national and European policies, market pressures, advisory and research services, and farmers’ networks also play a major role. These findings highlight the need for context-sensitive support or the need to address novel research gaps in IPM-related studies, especially in the Norwegian fruit farming context.
Forfattere
Alexander N. Hristov Andre Bannink M Battelli A Belanche M.C.C. Sanz G. Fernandez-Turren F. Garcia A. Jonker D.A. Kenny Vibeke Lind Sarah J. Meale D.M. Zilio C. Munoz David Pacheco Nico Peiren M. Ramin L. Rapetti Angela Schwarm S. Stergiadis K. Theodoridou Emilio M. Ungerfeld Sanne van Gastelen David R. Yanez-Ruiz Sinead M. Waters Peter LundSammendrag
No abstract has been registered
Forfattere
Alexander Hristov Andre Bannink Marco Battelli Alejandro Belanche M. Cecilia Cajarville Sanz Gonzalo Fernandez-Turren Florencia Garcia Arjan Jonker David A. Kenny Vibeke Lind Sarah J. Meale David Meo Zilio Camila Munoz David Pacheco Nico Peiren Mohammad Ramin Luca Rapetti Angela Schwarm Sokratis Stergiadis Katerina Theodoridou Emilio M. Ungerfeld Sanne van Gastelen David R. Yanez-Ruiz Sinead M. Waters Peter LundSammendrag
No abstract has been registered
Forfattere
Oliver Körner Alice Boarino Martina Friuli Dmitry Kechasov Elio Dinuccio Luisella Celi Xingjiang Zhang-SchneiderSammendrag
The re-usage of waste can strongly impact the environmental footprints of both the biogas production facility as waste-source and a receiver system as a greenhouse production. The waste product of the biogas-reactors as e.g. liquid and solid fertiliser. In a combined production with heated greenhouse-production both the main product biogas as well as its side products as water and the digestate are valuable compounds for a greenhouse production system. The impact of main and side products on the greenhouse produce depends on location, greenhouse type, and overall composition of the system. We analysed and modelled biogas-production of two biogas-greenhouse scenarios in Italy and Norway with each their specific input and outputs. For the two existing locations in Northern Italy (Trento; 46°04′N LAT) and Southern Norway (Sandefjord; LAT 59°08′N), and for a hypothetical location geographically between them (Berlin, Germany; 52°52′N) we analysed three scenarios of agricultural waste with either apple-juice production waste, waste from husbandry, or a mix of these two wastes; and their impact on environmental foot-prints of a tomato production in greenhouses. Scenarios were simulated with a greenhouse simulator, while simulation data was used as input to a consequential life cycle assessment. Functional unit was 1kg of tomato as gate.