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
Authors
Ararsa Derese SebokaAbstract
Energy systems in many low- and middle-income regions remained dominated by traditional biomass and fossil fuels, with significant implications for environmental sustainability, public health, and resource security. In Sub-Saharan Africa, and particularly in Ethiopia, biomass including firewood, charcoal, agricultural residues, and animal dung accounts for approximately 87% of total final energy consumption. Continued reliance on fuelwood and charcoal, combined with inefficient combustion technologies and unmanaged organic-waste disposal, contributed to deforestation, land degradation, greenhouse gas (GHG) emissions, and indoor air pollution. Methane emissions from open dumping of biodegradable waste further exacerbated climate impacts. Concurrently, population growth and rapid urbanization increased municipal solid-waste generation, of which a significant proportion comprises biodegradable and lignocellulosic fractions that remain largely untreated and underutilized. These converging pressures emphasized the need for integrated circular approaches that link waste management with renewable energy production, enabling recovery of value from lignocellulosic biomass while reducing environmental burdens. Lignocellulosic biomass represented a substantial yet underexploited renewable resource in Ethiopia. It is originating from agricultural residues, agro-industrial by-products, and service sector streams such as hotels and university campuses; these materials consist primarily of cellulose, hemicellulose, and lignin which are suitable for conversion into renewable energy carriers. However, most residues were disposed of through open dumping and informal burning, leading to uncontrolled emissions of methane and other greenhouse gases, air pollutants, localized soil and water contamination, and loss of recoverable energy. Effective valorization therefore required not only appropriate conversion technologies but also system-level integration that aligned feedstock characteristics, real-world energy demand, and environmental performance within a circular bioresource framework. The main objective of this PhD thesis was to evaluate the integrated circular valorization of lignocellulosic biomass into biogas and bio-briquettes and to assess the associated environmental implications in Southern Ethiopia. The research focused on hotels and university campuses as decentralized points where concentrated organic streams coexisted with continuous and predictable energy demand. By integrating national resource assessment, site-level energy and waste data, laboratory-scale solid-state anaerobic digestion (SS-AD) experimentation, and bio-briquette optimization, the thesis established a multi-scale framework for evaluating integrated circular valorization of lignocellulosic biomass in Southern Ethiopia.
Abstract
This study evaluated the agronomic performance of 15 plum cultivars grafted on both P. cerasifera and ‘Wangenheim Prune’ (P. domestica) seedling rootstocks over nine years at the Lithuanian Research Centre for Agriculture and Forestry. Trees on P. cerasifera were planted 4.5 m × 2.5 m apart, while those on ‘Wangenheim Prune’ were 4 m × 1.5 m apart. On average, trees on ‘Wangenheim Prune’ developed 23% smaller trunk diameters and produced 42% less pruning mass than those on P. cerasifera yet demonstrated higher yield efficiency, except for the ‘Valor’ cultivar, which performed better on P. cerasifera. Mean plot yield was about 40% higher on ‘Wangenheim Prune’. Based on productivity, survival, and fruit quality, the most promising cultivars for Nordic climates are ‘Čačanska Najbolja’ and ‘Jubileum’ on ‘Wangenheim Prune’, while ‘Valor’ was productive on both rootstocks. Leaf nutrient analyses revealed rootstock-dependent differences: leaves on P. cerasifera contained more P, K, Ca, and Mn, whereas Mg, Cu, and Zn were higher on ‘Wangenheim Prune’. Regardless of rootstock, trees grown in calcareous, high-pH soils were deficient in Fe and Mn.
Authors
Desalegn Chala Diress Tsegaye Alemu Habtamu Alem Belachew Asalf Tadesse Melesse Eshetu_Moges Nega Tassie Abate Ayalew Wondie Aklilu Tilahun Tadesse Abebayehu Aticho Alemu Gonsamo Lanhui Wang Erick Lundgren Jeffrey Kerby Jens Christian SvenningAbstract
Abstract Water hyacinth is among the world’s most damaging aquatic invasive plants, forming dense mats that disrupt ecosystem functioning, fisheries, navigation, and livelihoods across tropical and subtropical freshwater systems. Its rapid spread is driven by clonal propagation, short life cycles, and prolific seed production, particularly under nutrient-enriched conditions. Although mechanical, chemical, and biological control methods are widely applied, their long-term effectiveness remains uncertain when underlying eutrophication persists. Here, we present a large-scale, one-time water hyacinth removal campaign in Lake Tana, Ethiopia’s largest lake and a UNESCO Biosphere Reserve, as a representative nutrient-rich tropical freshwater system. Using high-resolution satellite imagery, we quantified coverage one month before removal, one month after removal, and one year later. We integrated SWOT (Strengths, Weaknesses, Opportunities, Threats) analysis with a socio-ecological system map to assess mitigation mechanisms and identify sustainable management pathways capable of providing long-term solutions to halt water hyacinth proliferation in freshwater bodies. The campaign removed over 75% (~1271 ha) of water hyacinth, yet within one year the plant resurged to levels ~18% higher than pre-removal. This rebound highlights the ecological resilience of water hyacinth and the limitations of short term, noncontinuous control strategies. Our analysis identifies unmanaged catchment nutrient inputs as the primary driver of proliferation. Lake Tana serves as a model system demonstrating that water hyacinth functions less as a traditional invader and more as a bioindicator of eutrophication. We propose a transferable conceptual and methodological framework combining continuous removal, catchment-based nutrient management, and circular bioeconomy approaches, offering globally relevant lessons for sustainable management of nutrient-enriched tropical freshwater systems.
Authors
Akhil Reddy Pashapu Sigridur Dalmannsdottir Marit Jørgensen Mallikarjuna Rao Kovi Odd Arne RognliAbstract
Timothy is the most important perennial forage grass species in northern Norway, a region that is predicted to experience variable winter weather conditions due to climate change. Knowledge about how timothy cultivars respond to a changing climate is crucial for safeguarding forage production at higher latitudes. In the current study, we investigated changes in gene expression under freezing and ice encasement stresses and SNP allele frequencies between temporal populations (seed generations) of the two northern-adapted timothy cultivars Engmo and Noreng. In general, there was a decrease in freezing tolerance (defined as LT 50 , the temperature lethal to 50% of the population) and an increase in ice encasement tolerance (defined as LD 50 , the duration lethal to 50% of the population) over time. Comparative transcriptome analyses identified several genes known to be involved in stress responses, such as ethylene-responsive transcription factors, dehydration-responsive element binding transcription factors, reversion to ethylene sensitivity 1, and abscisic acid repressor 1, as differentially expressed between the temporal populations of Noreng under freezing stress. Several loci with large allele frequency changes were observed to be in close proximity to the genes displaying patterns resembling shifts over time in Noreng. Very few gene expression differences between populations of both cultivars under ice encasement stress could be due to weak selection pressure during seed multiplication. There was a gradual decline in genetic diversity in populations of both cultivars over time. The results indicate that phytohormone-mediated transcriptional regulation might be one of the key mechanisms for adaptation to changing winter weather conditions at higher latitudes. These findings underscore the importance of monitoring genetic shifts during seed multiplication to maintain cultivar stability and suggest that the identified stress-responsive genes could serve as valuable targets for breeding climate-resilient forage crops.
Authors
Paloma Sánchez-Argüello Gema Sáez-Salto Alice Budai Pierre-Adrien Rivier Simon Weldon Antonio Martín-EstebanAbstract
Compost application is a widely recommended practice to maintain and improve soil fertility. However, such a practice could be a main entry path for plastic into soil. Accordingly, in the present work, two different compost samples, obtained with and without biochar, were analyzed to investigate how composting can affect the presence of microplastics (MPs). The substrate of both samples (consisting of a mixture of household food waste and animal manure) was also analyzed for comparative purposes. Samples were processed by oxidation, flotation, and filtration. MPs on the filters were observed, counted, and size-calibrated using both a stereomicroscope and an inverted microscope. MPs larger than 1 mm were further characterized by attenuated total reflectance Fourier-transformed infrared spectroscopy (ATR-FTIR). In parallel, mesoplastics (0.5–2 cm) were recovered from substrate and compost and extracted in methanol for testing in vitro cytotoxicity. The estimated concentration of MPs ranged from 820 to 1340 fragments/kg of dry sample, depending upon the sample. Three polymers represented the totality of identified plastic items: polyethylene (PE, including both low and high density), polyethylene terephthalate (PET), and polypropylene (PP) in order of abundance. Nevertheless, cytotoxicity was only observed in mesoplastic extracts from the substrate and could not be attributed to the identified plastic items themselves, suggesting that cytotoxic effects could have been caused by contaminants adsorbed to plastics or by the leaching of plastic additives during the extraction process. In summary, the composting process reduced the cytotoxicity of plastic extracts and the presence of MPs in compost, which could be attributed to the fragmentation of plastics.
Authors
Colin Sinclair Jemma Louise Wadham Laura Jaakola Sabina Strmic PalinkasAbstract
In recent years, rock powders have received renewed interest as slow-release fertilizers that can provide soils and crops with a range of macro- and micronutrients. Glacial flour is a naturally occurring, fine-grained rock powder that is found in glaciated regions worldwide. Formed from the erosion of bedrock, the physical and chemical properties of different glacial flours vary widely by source, influencing their effectiveness as fertilizers. This study aimed to analyze eight lithologically diverse glacial flours collected from glaciers in Iceland, Svalbard, and Norway for their exchangeable and total nutrient concentrations, trace metal concentrations and mineralogy. The flours were then applied to a nutrient-depleted, artificial soil at three application rates in a greenhouse experiment set up to mimic an Arctic/subarctic growing season for the crop, peas (Pisum sativum L.). The flours contained low amounts of plant-available N and P, while total P was highly variable. Glacial flour treatments, even at the lowest application rate of 2 tha-1, improved pea biomass and yield over the control, and were comparable to a low dose of a synthetic PK fertilizer. Increasing the application rate further was in some cases associated with an increase in biomass and yield. Trial results indicate that peas benefited from glacial flour amendment over a single growing season under conditions of severe nutrient limitation. Preliminary results suggest that glacial flour has potential utility in organic and regenerative agriculture, but suitable flours must be identified based on total nutrient concentrations, nutrient availability, dissolution rate, and potentially harmful trace metal concentrations
Authors
Giacomo Nicolini David Durden Luca Di Fiore Christopher Florian Simone Sabbatini Bert Gielen Arne Iserbyt Benjamin Loubet Ivan Mammarella Adriana Mariotti Maarten Op de Beeck Caleb Slemmons Carlo Trotta Adam Young Abad Chabbi Iris Feigenwinter Bernard Heinesch Natalia Kowalska Matthias Mauder Ladislav Šigut Michiel van der Molen Flavio Bastos Campos Daniel Berveiller Christian Brümmer Matthias Cuntz Jean‐Christophe Domec Benjamin Dumont Silvano Fares Damiano Gianelle Rasmus Jensen Carmen Kalalian Natascha Kljun Holger Lange Jean‐Marc Limousin Erik Lundin Antonio Manco Leonardo Montagnani Eiko Nemitz Matthias Peichl Erkka Rinne Marilyn Roland Marius Schmidt Guillaume Simioni Abin Thomas Caroline Vincke Dario PapaleAbstract
The lack of energy balance closure in Eddy‐Covariance (EC) measurements is a well‐known, still unresolved challenge in micrometeorology, with energy balance closure (EBC) rates typically ranging between 60% and 80%. While numerous hypotheses have been proposed to explain this imbalance, the relative contributions of neglected energy storage terms, data quality and flux processing options remain insufficiently disentangled. Using standardized ICOS and NEON datasets, we show that a significant portion of the observed energy imbalance can be attributed to overlooked or inconsistently handled energy components and turbulent flux quality control. Using data drawn from 84 sites, we show that comprehensive energy accounting—including soil heat flux, storage terms (soil, air, biomass), photosynthetic energy demand, and strict quality filtering of turbulent fluxes—improved EBC by 16% on average, with site‐specific gains up to 40%. However, we also identify a persistent residual imbalance that is unlikely to be resolved through methodological refinements or additional measurements alone, pointing to fundamental physical processes that are not accounted for in the standard measurement and processing. We argue that this unresolved imbalance should be explicitly acknowledged and bounded, rather than implicitly absorbed into correction schemes, and we outline practical guidance for diagnosing and interpreting EBC in standardized flux networks. This perspective evaluates methodological advances and residual uncertainties, providing an actionable framework for the appropriate use of EC energy fluxes in carbon, water, and climate research.
Authors
Hanna Huitu Tor-Einar Skog Christophe Pradal Antonio Calatayud Tor Skaslien Brita Linnestad Ari Ronkainen Christian Fournier Marc Labadie Dave Skirvin Matti Pastell David Melchior Johannes Tobiassen Langvatn Berit NordskogAbstract
Decision support systems (DSS) in crop protection provide valuable support for pest risk prognosis and recommendations for pest control, enabling farmers to make better-informed decisions. As a part of the European Union’s strategy for the sustainable use of plant protection products, the “IPM Decisions” project developed an online platform that gives farmers and advisors access to a wide range of DSS for major pests, weeds, and diseases in a variety of crops across Europe. Multiple DSS models relevant for different crops and geographical regions of Europe were selected for integration in the platform. Information on the models is compiled into a model catalogue, which serves as a core component of the IPM Decisions platform. To facilitate the use of these models, two application programming interfaces (APIs) were developed. In line with the FAIR (findable, accessible, interoperable, and reusable) principles, the DSS API provides access to models and their metadata, including descriptions of input and output parameters. The weather API enables access to European online weather data sources and adapts this data to meet the requirements of DSS models. While these APIs are integrated into the IPM decisions platform, they are also open source, allowing other crop protection and farm management software to inspect, download, modify, install, run, and use them. In this article, we describe the development of the DSS and weather APIs, outline their structure and definitions, and present the services that DSS API and weather API provide. Finally, we demonstrate their application through three practical use cases.
Authors
Milica Fotirić Akšić Dragana Dabić Zagorac Marko Kitanović Kristina Đorđević Maja Natić Oddmund Frøynes Mekjell MelandAbstract
Commercial production of sweet cherries is possible up to approximately 60° N latitude in Norway and is among the most economically important fruit crops in the country. The harvest is late, but yields are very high, and the fruit is intended solely for the fresh market. The objective of this study was to assess whether sweet cherry can be grown in pots and to determine fruit quality (sugar, acid, polyphenol, and mineral content) of three sweet cherry cultivars (‘Van’, ‘Lapins’, and ‘Regina’) grown in high tunnels with varying levels of fertigation (F) and the application of slow-release (SR) fertilisers. Trees were planted in 35 L plastic bags, trained as spindle trees, with a spacing of 1 × 2.5 m (4000 trees/ha). The tunnel was covered with polythene from flowering until harvest. Fruit produced in pots had low levels of sugars and acids and high levels of phenolic acids and flavonoids, while the mineral content depended on treatment and cultivar. The main sugar components (glucose and fructose), the sweetness index, phenolic acids (chlorogenic acid and ferulic acid), flavanols (catechin, rutin, quercetin, and hyperoside), and minerals (P, K, Mg, Ca, and Na) were much higher in the F treatment. SR treatments were more effective in increasing the content of acids (shikimic, malic, and quinic) and total phenolic content (TPC). Radical scavenging activity (RSA) and total sugars showed no statistically significant differences between the treatments studied. ‘Lapins’ fruit obtained from the fertigation regimes (when Kristalon brown + Calcinit + Magnesium-sulphate were added from mid-April to 1 September and plain water for the rest of the season, up to an electric conductivity (EC) of 0.5 and 1.0) contained the highest levels of minerals (P, K, Mg, Ca). The ‘Van’ cultivar from F treatments, especially VF2 (when Kristalon brown + Calcinit + Magnesium-sulphate were added from mid-April to 1 September and plain water for the rest of the season, with EC 1.0) and VF3 (when Kristalon brown is added in July, Kristalon brown + Calcinit + Magnesium-sulphate in August, and plain water for the rest of the season) had the highest sweetness index, glucose, fructose, chlorogenic acid, ferulic acid, and hyperoside in sweet cherry fruit. ‘Regina’ under the RSR1 (50 g Multicote and 30 g chalk lime per tree) and RSR2 regimes (100 g Multicote and 30 g chalk lime per tree) produced fruit with the highest acid components, RSA and TPC. This suggests that sweet cherry trees can be grown in pots under high tunnels, but nutrition should be adjusted for each cultivar according to its physiological responses to specific microclimate conditions.
Authors
Yasinta Beda Nzogela Joseph Maosa Marjolein Couvreur Mdili Katemani Charles Gervas Beartha Nguku Nessie Luambano Beatrice Kashando Danny Coyne John T. Jones Solveig Haukeland James Price Wim BertAbstract
No abstract has been registered