Publikasjoner
NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.
2024
Sammendrag
Aims To develop a methodology to study uptake and redistribution by plants of NH4+ from deep soil, applying it to investigate deep root N uptake by cultivated grassland species. Methods A slow-release 15NH4+ label adsorbed to clinoptilolite was placed into soil (depth 42 cm) well below the densest root zone in well-established monospecific stands of five grass and two clover species. Species showing a variety of deep rooting patterns, N acquisition strategy, forage qualities, and persistence in hemiboreal conditions were chosen. The label was placed in early spring and tracked throughout one or two growing seasons in two repeated experiments. Results After two growing seasons ~ 90% of the label was tracked in the soil and harvested herbage of grasses, less in clovers. Deep N uptake was limited in spring, increased during mid-season, and was strongest in autumn in all species, despite lower herbage yield in autumn. Species differed in ability to recover and maintain 15N in the soil–plant system. In one growing season, Lolium perenne L., Phleum pratense L., Schedonorus pratensis (Huds.) P.Beauv. and Schedonorus arundinaceus (Schreb.) Dumort herbage recovered ~ 65% of the label, Poa pratensis L. 54%, and Trifolium pratense L. and Trifolium repens L. 36–48%. Label transport to topsoil was observed, mainly attributable to plant nutrient redistribution rather than physical diffusion. Conclusions The innovative slow-release 15N label enabled tracing species differences and seasonal changes in uptake of NH4+ from deep soil. Among the tall-growing grasses, growth vigor appeared as important for deep N uptake as expected root depth.
Sammendrag
Stress on tree vitality is expected to increase due to climatic extremes in European forests. The decline in vitality of European beech (Fagus sylvatica L.) that has been reported recently, makes it necessary to rethink its future adaptive potential under ongoing climate change. Here we performed a pan European assessment of defoliation chronologies on 414 ICP Forests Level I beech plots, between 1995 and 2022. We investigated the temporal trends, spatial variation, tree-specific patterns as well as climate sensitivity of defoliation at plot level. Various trends emerged and we delineated the plots accordingly: 1) increasing defoliation trends indicating declining vitality (categorized as t1 plots); 2) no trends indicating stable crown condition (t2 plots); 3) decreasing defoliation trends indicating increase in vitality (t3 plots). Spatial variation was found among these plots but no regional grouping or clustering. Tree-specific patterns on 14 % plots were observed, characterized by an expressed population signal of < 0.85, indicating high inter-tree variability. Defoliation was found to be sensitive to climatic variables, mainly to temperature but also precipitation, albeit only for a small percentage of plots. Sensitivity was indicated by statistically significant (p<0.05) Pearson’s correlation coefficients. Moreover, this response depended on month of the year. Climate sensitivity of defoliation also varied across space and plots of different trend categories. It also differed along monthly water balance gradient, further indicating the role of site-specific water availability in mediating the responses to climatic variables. Our study provided basis for long-term defoliation studies, and is a crucial building block to assess beech vitality under potentially changing future climate. Furthermore, such studies will provide more insights into changes in sensitivity and adequate future sites for beech.
Sammendrag
The brown marine macroalga Alaria esculenta contains phlorotannins as polyphenolic compounds in its cell walls. This study aimed to understand their antioxidant effects on preserving the lipids in fillets of freshly-slaughtered farmed Atlantic salmon (Salmo salar). First, soluble phlorotannins were extracted from wild-grown population of A. esculenta in North Norway (Bodø) using solid/liquid extraction. A small-scale solid/liquid extraction (15 mg mL−1) with 70% acetone showed that 84% of total soluble phlorotannins (25.10 mg g−1 dry weight) were extracted after the first out of four extraction steps. In a large-scale extraction (3 mg 400 mL−1), the contents of soluble phlorotannins and the DPPH-based antioxidant capacities (measured as IC50) in 70% acetone- and water-based crude extracts were similar. Water is preferred extraction solvent for the following experiment because it complies with food safety standards, may minimise work procedures and is in accordance with the principles of Green Chemistry. Secondly, the antioxidant properties of the soluble phlorotannins were tested through incubating salmon fillets (Norwegian Quality Cuts) in water-based extracts. After six days of storage on ice, the peroxide value of Alaria-treated fillets was lower compared to the control (without Alaria-extract), while the p-anisidine and free fatty acid values remained unchanged. This indicates the phlorotannins’ inhibitory effect on the formation of primary rather than secondary lipid oxidation products. This study demonstrated that the antioxidant properties of the soluble phlorotannins extracted from A. esculenta using water can preserve the nutritional value of salmon fillets to extend the seafood’s shelf-life.
Sammendrag
Compared to fluctuating soil water (FW) conditions, stable soil water (SW) can increase plant water use efficiency (WUE) and improve crop growth and aboveground yield. It is unknown, however, how stable and fluctuating soil water affect root vegetables. Here, the effects of SW and FW were studied on cherry radish in a pot experiment, using negative pressure irrigation and conventional irrigation, respectively. The assessed effects included agronomic parameters, physiological indices, yield, quality and WUE of cherry radish. Results showed that under similarly average soil water contents, compared with FW, SW increased plant photosynthetic rate, stomatal conductance and transpiration rate, decreased leaf proline content by 13.7–73.3% and malondialdehyde content by 12.5–40.0%, and increased soluble sugars content by 6.3–22.1%. Cherry radish had greater biomass accumulation and nutrient uptake in SW than in FW. Indeed, SW increased radish output by 34.6–94.1% with no influence on root/shoot ratio or root quality. In conclusion, soil water stability affected directly the water physiological indicators of cherry radish and indirectly its agronomic attributes and nutrient uptake, which in turn influenced the crop biomass and yield, as well as WUE. This study provides a new perspective for improving agronomy of root crops and WUE through managing soil water stability.
Forfattere
Qiang Liu Haoyu Zhang Haozhen Wang Shenggeng Zhao Yeqing Li Lu Feng Junting Pan Hongjun Zhou Chunming XuSammendrag
Anaerobic digestion (AD), as a crucial technology for organic waste resource recovery, faces the challenge of low efficiency in converting high-load organic substance into biogas. In this study, high-load AD system with food waste and excess sludge as co-substrates was constructed. The effect and mechanism of carbon quantum dots (CQD) derived from straw in promoting the performance of AD systems have been studied. The oxidation pretreatment of straw with H2O2 and acetic acid increased the yield of hydrothermal synthesis CQD to approximately 40%. The effect of different CQD on CH4 yield performance was further explored. The cumulative CH4 yield performance of the fermenter was improved after adding CQD. The CQD synthesized from pretreated straw and the nitrogen-doped CQD synthesized using Chlorella as the nitrogen source showed competitive promotion performance, increasing cumulative CH4 yield by 17.71% and 8.87%, respectively. These CQD can effectively accelerate the degradation of dissolved organic matter and thus improve the CH4 yield performance, with the most significant effect of CQD synthesized from pretreated straw. Electrochemical analysis and the correlation analysis between microorganisms and performance parameters showed that these CQD established an electron conductive network to enhance the electron transfer of the system. This well conductive conditions enriched hydrogenotrophic methanogenic (Methanosarcina), electroactive bacteria (Clostridium_sensu_stricto_1), and hydrolytic-acidifying bacteria (norank_f__Bacteroidetes_vadinHA17). This study significantly enhanced the yield of straw-derived CQD through green methods, and deeply revealed the potential promoting mechanisms of biomass-derived CQD by investigating the correlation between system performance and microorganisms in high-load AD systems.
Redaktører
Habtamu AlemSammendrag
In the face of unprecedented challenges posed by the global COVID-19 pandemic, Resilience and Realities - Exploring Pandemic Effects, Governance Challenges, and Economic Insights offers a comprehensive exploration of the intricate interplay between public policies and uncertain times. This enlightening volume presents a thought-provoking collection of chapters that dissect the illusions, opportunities, and complexities surrounding public policies during crises. Spanning two captivating sections, this book embarks on a journey through the labyrinth of pandemic-related public policies, offering fresh insights into the ever-evolving landscape of economic responses and the resilient spirit of entrepreneurship. In the first section, “Illusions of Public Policies Amidst a Pandemic”, readers are invited to dissect the enigma of navigating uncertainties in crisis management. Delve into the gendered impact of the pandemic on academic women, explore the untapped opportunities within the pandemic’s wake, and scrutinize the efficacy of governmental economic strategies. The second section, “Public Policies towards Investment, Technology, and Efficiency”, provides an insightful investigation into the impact of investment in human capital on economic growth. Review the intricacies of financial management within the public sector and gain an understanding of the multifaceted dimensions of technology, investment, and efficiency in public policies. With each chapter, esteemed authors contribute their expertise to illuminate the complexities of these critical topics. Resilience and Realities - Exploring Pandemic Effects, Governance Challenges, and Economic Insights is a vital resource for policymakers, economists, academics, and curious minds seeking a deeper understanding of the intricate nexus between public policies and uncertain times. Explore the wealth of knowledge and insights within these pages and embark on a journey toward a more informed and resilient future. Discover illuminating perspectives, engage in thought-provoking analyses, and embrace the ever-changing landscape of public economics. This book stands as a beacon of knowledge and enlightenment in an era of unprecedented challenges.
Sammendrag
Som drøvtyggar har sauen evne til å omdanna fiberrikt fôr, som ikkje er eteleg for menneske, til høgverdig protein, i kjøtt og biprodukt, med essensielle aminosyrer. I norsk sauehald er det meste av fôrgrunnlaget grovfôr, og beite står for om lag 60 % av fôrinntaket. Men det blir også brukt ein del kraftfôr og mjølkeerstatningar med humant etelege ingrediensar. I denne studien undersøkte vi kor mykje eteleg protein vi får ut i høve til mengd eteleg protein gitt i fôringa. Effektiviteten er rekna som høvetalet (HePeff) med mengd eteleg protein i kjøtt, blod og innmat i høve til mengd eteleg protein brukt i fôringa. Dersom det blir produsert meir eteleg enn det som blir brukt i fôringa, er effektiviteten HePeff større enn 1. Det blei også estimert i kor stor grad aminosyrer brukt i fôringa blir oppgradert til essensielle aminosyrer for menneske. Dette uttrykt som differansen mellom fordøyelege essensielle aminosyrer i kjøtt, blod og innmat og mengd av dei same aminosyrene brukt i fôringa. Datagrunnlaget var tal frå sauebruk som var med i Driftsgranskingane i jordbruket i åra 2018-2020. Mengd innkjøpt kraftfôr og mjølkeerstatning blei estimert ut frå rekneskapstal. Ingrediensar i innkjøpt fôr blei estimert ut frå opplysningar gitt av fôrprodusentar. I kalkylane såg ein på kva det hadde å seie om raps og rapsprodukt i kraftfôret vart rekna som humant eteleg. Dersom ein rekna at både kjøtt, blod og innmat er eteleg, og rapsprodukt ikkje er humant eteleg, blei det i gjennomsnitt produsert om lag like mykje humant eteleg protein som brukt i fôringa, HePeff = 1. Dersom ein ikkje rekna proteinet i raps som humant eteleg, blei det for alle fordøyelege essensielle aminosyrer produsert meir enn brukt i fôringa i regionane ‘Austlandet andre bygder’ og ‘Trøndelag andre bygder’, medan det for andre deler av landet var om lag same mengd protein i kjøtt og biprodukt som det vart brukt i fôringa. Proteineffektiviteten var høgare i regionar med gode utmarksbeite, og Fjell- og dalbygder i Trøndelag og på Austlandet hadde høgare HePeff enn Agder og Rogaland. Mengd kraftfôr per vinterfôra sau og tal gangslam (levande lam på hausten) per vinterfôra sau hadde sterk effekt på HePeff, og det er fullt mogleg å betre effektiviteten med relativt små justeringar av mengd og type ingrediensar i kraftfôr.
Forfattere
Stacey M. Trevathan-Tackett Sebastian Kepfer-Rojas Martino Malerba Peter I. Macreadie Ika Djukic Junbin Zhao Erica B. Young Paul H. York Shin-Cheng Yeh Yanmei Xiong Gidon Winters Eilat Campus Danielle Whitlock Carolyn A. Weaver Anne Watson Inger Visby Jacek Tylkowski Allison Trethowan Scott Tiegs Ben Taylor Jozef Szpikowski Grazyna Szpikowska Victoria L. Strickland Normunds Stivrins Ana I. Sousa Sutinee Sinutok Whitney A. Scheffel Rui Santos Jonathan Sanderman Salvador Sánchez-Carrillo Joan-Albert Sanchez-Cabeza Krzysztof G. Rymer Ana Carolina Ruiz-Fernandez Bjorn J. M. Robroek Tessa Roberts Aurora M. Ricart Laura K. Reynolds Grzegorz Rachlewicz Anchana Prathep Andrew J. Pinsonneault Elise Pendall Richard J. Payne Ilze Ozola Cody Onufrock Anne Ola Steven F. Oberbauer Aroloye O. Numbere Alyssa B. Novak Joanna Norkko Alf Norkko Thomas J. Mozdzer Pam Morgan Diana I. Montemayor Charles W. Martin Sparkle L. Malone Maciej Major Mikolaj Majewski Carolyn J. Lundquist Catherine E. Lovelock Songlin Liu Hsing-Juh Lin Ana Lillebo Jinquan Li John S. Kominoski Anzar Ahmad Khuroo Jeffrey J. Kelleway Kristin I. Jinks Daniel Jerónimo Christopher Janousek Emma L. Jackson Oscar Iribarne Torrance Hanley Maroof Hamid Arjun Gupta Rafael D. Guariento Ieva Grudzinska Anderson da Rocha Gripp María A. González Sagrario Laura M. Garrison Karine Gagnon Esperança Gacia Marco Fusi Lachlan Farrington Jenny Farmer Francisco de Assis Esteves Mauricio Escapa Monika Domańska André T. C. Dias Carmen B. de los Santos Daniele Daffonchio Pawel M. Czyryca Rod M. Connolly Alexander Cobb Maria Chudzińska Bart Christiaen Peter Chifflard Sara Castelar Luciana S. Carneiro José Gilberto Cardoso-Mohedano Megan Camden Adriano Caliman Richard H. Bulmer Jennifer Bowen Christoffer Boström Susana Bernal John A. Berges Juan C. Benavides Savanna C. Barry Juha M. Alatalo Alia N. Al-Haj Maria Fernanda AdameSammendrag
Patchy global data on belowground litter decomposition dynamics limit our capacity to discern the drivers of carbon preservation and storage across inland and coastal wetlands. We performed a global, multiyear study in over 180 wetlands across 28 countries and 8 macroclimates using standardized litter as measures of “recalcitrant” (rooibos tea) and “labile” (green tea) organic matter (OM) decomposition. Freshwater wetlands and tidal marshes had the highest tea mass remaining, indicating a greater potential for carbon preservation in these ecosystems. Recalcitrant OM decomposition increased with elevated temperatures throughout the decay period, e.g., increase from 10 to 20 °C corresponded to a 1.46-fold increase in the recalcitrant OM decay rate constant. The effect of elevated temperature on labile OM breakdown was ecosystem-dependent, with tidally influenced wetlands showing limited effects of temperature compared with freshwater wetlands. Based on climatic projections, by 2050 wetland decay constants will increase by 1.8% for labile and 3.1% for recalcitrant OM. Our study highlights the potential for reduction in belowground OM in coastal and inland wetlands under increased warming, but the extent and direction of this effect at a large scale is dependent on ecosystem and OM characteristics. Understanding local versus global drivers is necessary to resolve ecosystem influences on carbon preservation in wetlands.
Sammendrag
Context Traditional critical nitrogen (N) dilution curve (CNDC) construction for N nutrition index (NNI) determination has limitations for in-season crop N diagnosis and recommendation under diverse on-farm conditions. Objectives This study was conducted to (i) develop a new rice (Oryza sativa L.) critical N concentration (Nc) determination approach using vegetation index-based CNDCs; and (ii) develop an N recommendation strategy with this new Nc determination approach and evaluate its reliability and practicality. Methods Five years of plot and on-farm experiments involving three japonica rice varieties were conducted at fourteen sites in Qixing Farm, Northeast China. Two machine learning (ML) methods, random forest (RF) and extended gradient boosting (XGBoost) regression, were used to fuse multi-source data including genotype, environment, management, growth stage, normalized difference vegetation index (NDVI) and normalized difference red edge (NDRE) from portable active canopy sensor RapidSCAN. The CNDC was established using NDVI and NDRE instead of aboveground biomass (AGB) measured by destructive sampling. A new in-season N diagnosis and recommendation strategy was further developed using direct and indirect NNI prediction using multi-source data fusion and ML models. Results The new CNDC based on NDVI or NDRE explained 94−96 % of Nc variability in the evaluation dataset when it was coupled with environmental and agronomic factors using ML models. The ML-based PNC and NNI prediction models explained 85 % and 21–36 % more variability over simple regression models using NDVI or NDRE in the evaluation dataset, respectively. The new in-season N diagnosis strategy using the NDVI and NDRE-based CNDCs and plant N concentration (PNC) predicted with RF model and multi-source data fusion performed slightly better than direct NNI prediction, explaining 7 % more of NNI variability and achieving 89 % of the areal agreement for N diagnosis across all evaluation experiments. Integrating this new N management strategy into the precision rice management system (as ML_PRM) increased yield, N use efficiency (NUE) and economic benefits over farmer’s practice (FP) by 7–15 %, 11–71 % and 4–16 % (161–596 $ ha−1), respectively, and increased NUE by 11–26 % and economic benefits by 8–97 $ ha−1 than regional optimum rice management (RORM) under rice N surplus status under on-farm conditions. Conclusions In-season rice N status diagnosis can be improved using NDVI- and NDRE-based CNDC and PNC predicted by ML modeling with multi-source data fusion. Implications The active canopy sensor- and ML-based in-season N diagnosis and management strategy is more practical for applications under diverse on-farm conditions and has the potential to improve rice yield and ecological and economic benefits.
Forfattere
Sanjana De Zoysa Jeewanthi Sirisena Helani Perera Shalinda Fernando Miyuru Gunathilake Upaka RathnayakeSammendrag
Rainfall Intensity Duration Frequency (IDF) curves can be identified as a major role in the planning of urban drainage infrastructure. Sri Lanka, which is an island surrounded by the Indian Ocean, is frequently exposed to various climatic alterations. Sri Lanka has specific region-wise IDF relationships for the entire country, however, these IDF curves were developed more than 30 years ago. Many in-situ rainfall observations in Sri Lanka have insufficient record lengths and the absence of finer time scale records (e.g. 15 min, hourly) leading to unreliable IDF curve developments. Given this importance, the present paper demonstrates the application of Satellite-based Precipitation Product (SbPP) daily rainfall in developing IDF curves for Sri Lanka. Rainfall satellite estimates derived from Integrated Multi-satellite Retrievals for GPM (IMERG), Tropical Rainfall Measuring Mission (TRMM-3B42), and Precipitation Estimation from Remotely Sensed Information Using Artificial Neural Networks – Climate Data Record (PERSIANN-CDR) have been used to evaluate the ability of application of remote sensing data to develop IDF curves for Sri Lanka against rain gauge (RG) data. Our study breaks new ground by generating 50 IDF curves tailored to specific locations covering the whole county Sri Lanka, using daily rainfall data from RGs and three SbPPs during the period between 1990 and 2019. This marks a significant departure from the conventional approach, offering a more granular understanding of rainfall patterns in the country. By providing IDF curves for individual locations, our research presents a novel contribution to Sri Lanka's IDF history. At first, to evaluate the accuracy of SbPPs, statistical analysis was conducted using continuous and categorical evaluation indices. Second, IDF curves were developed and compared with the presently available IDF curves. Results showcased that IMERG outperformed all SbPPs, while PERSIANN-CDR showed dire performances. The IMERG and TRMM-3B42 products tend to overestimate light precipitation regions in high elevations and overestimate heavy rainfall in low elevations compared to rain gauge data. Rainfall intensities derived by rain gauge data depicted relative changes within ±30% for shorter durations and ±20% for longer durations while SbPPs showed beyond ±30% difference concerning the previously developed IDFs. It was apparent that these products have significant inaccuracies which cannot be neglected when utilizing them in developing IDF curves. This study will be beneficial in solving design problems associated with urban runoff control and disposal where knowing the rainfall intensities of different return periods with different durations is vital.