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
Linn VassvikAbstract
Agricultural production is highly dependent upon pollinators to achieve maximum yield and increase global food security. Wild pollinators, such as bees, are declining due to a loss of habitat from agricultural intensification, and the use of domesticated honeybees to supplement pollination services is increasing. Apple is an important, pollinator dependent food crop that commonly experiences pollination and production deficits worldwide. In this thesis, I explored whether pollination and production deficits occur in Norwegian apple orchards and what factors might be driving potential deficits. To test for pollination (seed set) and production (yield) deficits I conducted a supplemental pollination experiment for three cultivars, in eighteen orchards, in two distinct growing regions in Norway, over two years. I also assessed which pollinators are present in Norwegian apple orchards and how different groups of bees and their behaviour affect pollination of apple. Lastly, I studied different management practices to increase bee diversity and pollination success, by increasing alternate floral resources and evaluating orchard design that promotes cross-pollination. Pollination and production deficits were found across all locations, with differences in pollination deficits among cultivars. I also found that a high abundance of wild bees increases seed set in apples—a key indicator of pollination success. Behaviour also varied among bee groups, for example bumblebees visited more flowers, while solitary bees were slow, but potentially more thorough, foragers, which increases pollen deposition. Wild bees visited more apple flowers than dandelion flowers (Taraxacum spp.) when orchards were left unmowed. I also found that a higher abundance of dandelions increased bee visitation to apple flowers, suggesting higher floral diversity can increase pollination success and support a greater diversity of bees. In addition, block design orchards appear to limit cross-pollination among apple cultivars, and management actions to decrease the distance among compatible apple cultivars is needed to achieve sufficient pollination. Overall, my results suggest that greater pollination and production of apples in Norway is possible, and management actions should focus on increasing wild bee abundance and diversity, increasing alternate floral resources, and optimising orchard design to facilitate cross-pollination across shorter distances. Such actions have the potential to ensure greater yields of higher quality apples for human consumption and increased economic output for farmers.
Authors
Terje Christensen Are Røysamb Ulrike Bayr Dieu Tien Bui Guðrún Helgadóttir Nina Johansen Joern Klein Mieke Cornelia Louwe Randi Mork Kyungbinn Noh Stefanie Reinhardt Trude Eid Robsahm Kristin Helen Roll Øyvind Steifetten Per Strömberg Gry Tengmark Østenstad Veronika ZaikinaAbstract
Abstract Energy-efficient lighting solutions, while beneficial for reducing energy consumption, also pose challenges in terms of light pollution. Light pollution, defined as excessive or misdirected artificial light, has become a significant environmental issue globally. This perspective paper explores the extent, effects, and knowledge gaps related to light pollution, with a focus on its impact on human health, ecosystems, and energy consumption. This study focuses on Norway, a country that is particularly relevant for studying light pollution due to its far northern location. At high latitudes, the variation in natural light is larger over the year than at lower latitudes. Therefore, a Nordic perspective is valuable to present knowledge about effects of artificial lighting under these conditions. Under the midnight sun, minimal additional outdoor lighting is required, whereas during the winter season, outdoor lighting may be utilised continuously. The paper synthesizes findings from various studies, highlighting the rapid increase in light pollution due to urbanisation, infrastructure development, and the widespread adoption of LED technology. Human health effects include alterations of circadian rhythms, increased risk of accidents, and potential links to serious diseases such as cancer. Ecosystem impacts are profound, affecting a number of species i.e., within insects and bats, and may lead to for instance disturbances in navigation and circadian rhythms, habitat fragmentation, and altered predator–prey dynamics. This article identifies significant knowledge gaps, particularly in the measurement of light pollution, understanding its health effects, and its impact on various species. Recommendations for future research and policy development are provided, emphasising the need for interdisciplinary approaches to mitigate the adverse effects of light pollution and promote sustainable lighting practices.
Authors
James O’Malley John A. Finn Carsten S. Malisch Matthias Suter Sebastian T. Meyer Giovanni Peratoner Marie-Noëlle Thivierge Diego Abalos Paul R. Adler T. Martijn Bezemer Alistair D. Black Åshild Ergon Barbara Golińska Guylain Grange Josef Hakl Nyncke J. Hoekstra Olivier Huguenin-Elie Jingying Jing Jacob M. Jungers Julie Lajeunesse Ralf Loges Gaëtan Louarn Andreas Lüscher Thomas Moloney Christopher K. Reynolds Ievina Sturite Ali Sultan Khan Rishabh Vishwakarma Yingjun Zhang Feng Zhu Caroline BrophyAbstract
High-yielding forage grasslands frequently contain low species diversity and receive high inputs of nitrogen fertilizer. To investigate multispecies mixtures as an alternative strategy, the 26-site international LegacyNet experiment systematically varied the diversity of sown grasslands using up to six high-yielding forage species (grasses, legumes, and herbs) managed under moderate nitrogen inputs. Multispecies mixtures outyielded two widely used grassland practices: a grass monoculture with higher nitrogen fertilizer and a two-species grass-legume community. High yields in multispecies mixtures were driven by strong positive grass-legume and legume-herb interactions. In warmer sites, the yield advantage of legume-containing multispecies mixtures over grass monocultures with higher nitrogen fertilizer inputs increased. Improved design of grassland mixtures can inform more environmentally sustainable forage production and may enhance adaptation of productive grasslands to a warming climate.
Authors
Palingamoorthy Gnanamoorthy Junbin Zhao Yajun Chen Linjie Jiao Boonsiri Sawasdchai Zhang Jing Abhishek Chakraborty Pramit Kumar Deb Burman Sung‐Ching Lee Thomas A. M. Pugh Yiping Zhang Qinghai SongAbstract
ABSTRACT Increasing drought frequency and intensity affect biophysical functions of natural ecosystems. In tropical semi‐arid savannas, while immediate drought effects are well‐studied, the drought legacy effects on vegetation composition and associated ecosystem functions remain unclear. We used data of vegetation composition, net ecosystem CO 2 exchange, surface albedo and evapotranspiration (ET) in 2017–2022 from a savanna ecosystem, Southwest China, to investigate the legacy effect of an extreme drought event that occurred in 2019. Vegetation declined continuously for 3 post‐drought years. While tree numbers declined by 12%, shrub numbers dropped by 50% compared with pre‐drought levels, shifting vegetation dominance toward trees. This structural change caused sustained reductions in albedo and ET, which remained below pre‐drought levels, despite gross primary production recovering in the years immediately post‐drought. Vegetation shifts disproportionately impact ecosystem functions, with energy and water fluxes exhibiting greater vulnerability and potentially enhancing regional warming as droughts increase in Asian savannas.
Authors
Caio Nunes Gonçalves Felipe José Cury Fracetto William Ramos da Silva Thiago Inagaki Renato Lemos dos Santos Giselle Gomes Monteiro Fracetto Ademir de Oliveira FerreiraAbstract
Sewage sludge-derived biochar, a carbon-rich material produced by the pyrolysis of sewage sludge, has emerged as a promising amendment for enhancing the fertility and biological quality of nutrient-poor sandy soils in tropical regions. We investigated the effects of sewage sludge (SS) and its biochar (SSB) on microbial indicators, nutrient dynamics, and sugarcane biomass growth in sandy soil over 120 days. Treatments included individual applications of SS (40 Mg ha−1) and SSB (20 Mg ha−1), their combinations at 75:25, 50:50, and 25:75 SS:SSB ratios, a mineral fertilizer, and an unfertilized control. Microbial biomass carbon (Cmic), basal C-CO2 flux, metabolic (qCO2) and microbial (qMic) quotients were monitored, along with ammonium and nitrate levels, available phosphorus (P), and carbon stock. SS promoted a rapid rise in microbial activity and Cmic, whereas SSB sustained these effects over time, demonstrating complementary roles. The 75:25 combination exhibited the strongest synergistic response, enhancing microbial efficiency (higher qMic and lower qCO2), P availability, and carbon storage. Ammonium and nitrate peaked during early and mid-stages, respectively, with the highest values under SS. At the same time, P availability and soil carbon stocks were maximized under 75:25. Sugarcane biomass increased significantly in this treatment, despite foliar N and P concentrations remaining below sufficiency levels. These results highlight clear synergistic interactions between SS and SSB, emphasizing that the 75:25 combination offers a balanced strategy to improve nutrient cycling, microbial functionality, and carbon stabilization in tropical sandy soils.
Abstract
Cover crops enhance soil quality and organic matter stability, yet the mechanisms linking belowground inputs to persistent soil organic matter (SOM) remain unclear. This study examined the effects of diversified cover cropping in barley systems on root biomass, SOM fractions, soil structure, microbial activity, and yield in central Norway (63.9° N), three years post-implementation. Six treatments were tested: (1) Control (barley without NPK), (2) Biochar-Fertilizer (barley + NPK + 3 Mg ha⁻¹ biochar), (3) Monocrop (barley), (4) Ryegrass (barley + ryegrass), (5) Clover (barley + ryegrass + white/red clover), and (6) Chicory (barley + ryegrass + red clover + chicory + bird’s-foot trefoil). Ryegrass and Clover systems produced 28.65 g m-² more root biomass at 0–13 cm (p < 0.05) and, along with Monocrop, stored 2.2 Mg ha-¹ more mineral-associated organic matter (MAOM) carbon and 0.2 Mg ha-¹ more MAOM nitrogen at 0–20 cm than other treatments. The Chicory system improved soil structure and biology, with higher aggregate stability, lower bulk density, and greater microbial abundance. Barley yields remained consistent across treatments, suggesting that cover cropping and low biochar inputs do not reduce productivity. Strong correlations (p < 0.01) between root biomass and MAOM stocks highlight root development as a key driver of SOM stabilization via organo-mineral associations. These findings underscore the role of root-enhancing cover crops in promoting MAOM formation and long-term SOM persistence, offering valuable insights for sustainable soil management.
Abstract
No abstract has been registered
Authors
Seth J. Dorman Hannah M. Rivedal David J. Maliszewski Todd N. Temple Casey Cruse Jing Zhou Pete A. Berry Robert J. Starchvick Chloe Oshiro Nicole P. AndersonAbstract
Epidemiology and management of aphid-transmitted yellow dwarf viruses (YDVs) have received international attention in small grain crops over the past century. However, focused research regarding YDV management in grass seed production systems, including perennial ryegrass (Lolium perenne L.), is limited. An integrated pest management program is needed to reduce the impact of the aphid-YDV complex in perennial grass seed crops. The objectives of the study were to evaluate the effects of nitrogen fertilizer rate, and the timing and frequency of foliar insecticide applications on aphid abundance, YDV disease incidence, and seed yield in two perennial ryegrass cultivars in small-plot field trials from 2021 to 2024. Trade-offs in economic returns across treatment combinations and YDV detection using remote sensing were also observed. Aphid and natural predator densities varied across foliar insecticide treatments. The high nitrogen rate increased YDV incidence across three field seasons in both cultivars. Seed yield and economic returns were greatest for the less susceptible cultivar when fully protected with one insecticide treatment per season (autumn, spring, and summer). A higher-than-recommended nitrogen rate did not increase seed yield across treatment combinations in first-year stands; however, an increase was observed in second- and third-year stands when YDV infection averaged >50%. Selecting resistant cultivars and reducing aphid populations during the autumn and spring aphid flights is critical for maximizing seed yield potential in perennial ryegrass. Furthermore, a lower nitrogen rate can be used in first-year stands to save input costs with no impact on seed yield potential.
Authors
Johannes BreidenbachAbstract
No abstract has been registered
Authors
Sissel Hansen Synnøve Rivedal Samson Øpstad Johannes Deelstra Trond Børresen Torfinn Torp Peter DörschAbstract
No abstract has been registered