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
Abstract
Background The soil-borne oomycete Phytophthora cactorum causes crown rot, a major disease of the allo-octoploid strawberry (Fragaria × ananassa Duch., 2n = 8× = 56) that limits cultivation worldwide. Resistance to P. cactorum is a highly desirable trait but is typically quantitative and moderately heritable. A better understanding of the genetic basis of resistance to crown rot is essential for developing durable crown rot-resistant cultivars. Results We conducted a genome-wide association study (GWAS) using multi-locus models on 100 wild strawberry accessions from South and North America. The accessions were genotyped using the Axiom™ 50 K strawberry SNP array and mapped to the F. × ananassa cv. Royal Royce v. 1.0 reference genome. Testing for resistance to P. cactorum revealed a wide range of phenotypes. A single genetic marker, AX-184528282, located on chromosome 7B, was strongly associated with resistance to P. cactorum and explained 53% of the observed phenotypic variation. This marker was present in several highly resistant exotic Fragaria accessions that represent potential donors for introgression of favorable alleles into modern strawberry cultivars. In addition, several strong candidate resistance genes were identified within the 2 Mb genomic region surrounding the significant marker. Conclusions This study advances understanding of resistance to P. cactorum in strawberry and identifies genetic resources that can accelerate the development of crown rot-resistant cultivars through marker-assisted breeding.
Abstract
In plain regions, nitrogen (N) leaching from agricultural land during wet seasons is a major source of diffuse pollution. Clarifying the impact of different land types on the migration of water and N in the soil would be of great help for alleviating N pollution. Using combined approaches of field monitoring, literature review and farmer surveys, this study analyzed water and N dynamics within the 0–100 cm soil profile during the rainy season, N surplus and risk of N leaching across four land uses in North China Plain: grain field, vegetable field, woodland, and orchard. The results showed that: (1) Dynamics of soil water storage (SWS) followed patterns of precipitation and peaked at the end of the rainy season (September), with the highest value in vegetable field (380 mm), followed by orchard (368 mm), woodland (346 mm), and grain field (324 mm). (2) Nitrate (NO₃⁻-N) migrated downward with infiltrating rainfall, causing post-season declines in surface soils (0–40 cm) and concurrent increases in subsurface layers (40–100 cm), evidencing rainfall-driven translocation. (3) Orchard and woodland (502 and 494 kg N ha⁻¹) had much greater estimated N losses than grain and vegetable fields (87 and 38 kg N ha⁻¹), due to significantly higher NO₃⁻-N accumulation in the former (p < 0.05). These results highlighted that intensive rainfall and long-term high fertilization in non-grain systems, particularly orchard and woodland, substantially elevated N leaching risks. Improved management strategies that limit N buildup and mitigate intensive rainfall-induced leaching are urgently needed to curb agricultural N pollution.
Abstract
The sustainability transitions literature suggests that individual firms struggle to move toward sustainability unless the broader socio-economic system also evolves. Despite firms' willingness to change, existing systemic challenges often impede their progress. This paper employs paradox theory to address this struggle and examines how firms balance economic and societal concerns in their transition from business thinking to sustainability thinking. Based on a qualitative case study of the food industry's collaboration initiatives on food waste reduction and prevention in Norway, the study identifies the systemic challenges and sustainability paradoxes that the industry faces. We find that the firms' efforts to reduce food waste collide with established food industry agreements, standards, business strategies, regulations, and agricultural policies, impeding a systemic and structural transformation of the industry. The paper discusses how the food industry may navigate these challenges collectively and draws implications for the sustainability transitions literature. Primarily, the conclusions signal a need for governance and incentive structures at the system level beyond the action space of individual firms, and secondarily, illustrate how such governance approaches to sustainability transitions are sector-specific and geographically embedded.
Abstract
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.
Authors
Dafni Foti Stephen Amiandamhen Eleni Voulgaridou Elias Voulgaridis Costas Passialis Stergios AdamopoulosAbstract
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.
Abstract
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
Abstract
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.
Abstract
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.
Abstract
presentasjon seminar
Authors
Sartre, Liane MoniqueAbstract
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.