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.
2023
Abstract
Closing nutrient cycles by bio-based fertilizer products (BFPs) can improve the environmental sustainability of food systems and facilitate a more circular economy. Although the theoretical potential for nutrient recycling has been explored in detail, BFPs still seldom replace mineral fertilizer products in practice. The aim of the present study was to explore the critical enabling and limiting factors for the use of BFPs as seen from the perspective of farmers, suppliers, and civil society. To this aim, qualitative interviews were conducted with seven conventional grain farmers, six suppliers of BFPs, and five representatives of civil society, limited to environmental non-governmental organizations. The presented results illustrate a mismatch between demand and supply. On the one hand, the interviewed farmers were only interested in using BFPs if they are practical to use, balanced with respect to nutrient contents, and potentially provide the same earnings as mineral fertilizers. Positive effects for soil quality were an important driver for many of the farmers. On the other hand, the suppliers of BFPs were generally not able to offer products that fulfilled the farmers’ demands without economic losses, and they emphasized that they have faced several regulatory challenges. Representatives of regional civil society organizations expressed concern that new technical solutions could cause new environmental challenges, and that BFPs could enable further intensification of livestock production. The central-level representatives from the same NGOs, however, were positive about that BFPs can solve environmental problems. Policy instruments will be needed to increase the adoption of PFPs. Fostering BFPs’ that contribute to a sustainable agriculture is important to consider when formulating these polices.
Abstract
Livestock husbandry has raised enormous environmental concerns around the world, including water quality issues. Yet there is a need to document long-term water quality trends in livestock-intensive regions and reveal the drivers for the trends based on detailed catchment monitoring. Here, we assessed the concentration and load trends of dissolved reactive phosphorus (DRP) in streamwater of a livestock-intensive catchment in southwestern Norway, based on continuous flow measurements and flow-proportional composite water sampling. Precipitation and catchment-level soil P balance were monitored to examine the drivers. At the field level, moreover, the relationship between soil P balance and soil test P (measured using the ammonium lactate extraction method, P-AL) was assessed. Results showed that on average of 20 years 95 % of the P was applied to the catchment during March–August, when 40 % of annual precipitation and 25 % of annual discharge occurred. The low runoff helped reduce P loss following P applications. However, flow-weighted annual mean DRP concentration significantly increased with increasingly cumulative soil P surplus (R2 = 0.55, p = 0.0002). With a mean annual P surplus of 8.8 kg ha−1, the annual mean DRP concentration (range: 49–140 μg L−1; mean: 80 μg L−1) and annual DRP load (range: 0.35–1.46 kg ha−1; mean: 0.65 kg ha−1) significantly increased over the 20-year monitoring period (p = 0.001 and 0.0003, respectively). At the field level, P-AL concentrations were positively correlated with soil P balances (R2 = 0.48, p < 0.0001), confirming the long-term impact of P balances on the risks of P loss. The study highlights the predominant role of long-term P balances in affecting DRP loss in livestock-intensive regions through the effect on soil test P.
Abstract
No abstract has been registered
Authors
Jian Liu Faruk Djodjic Barbro Ulen Helena Aronsson Robert Barneveld Marianne Bechmann Lars Bergström Tore Krogstad Sigrun Hjalmarsdottir Kværnø Katarina Kyllmar Anne Falk Øgaard Lillian Øygarden Eva SkarbøvikAbstract
No abstract has been registered
2022
Abstract
Three strains of chlorophyte microalgae indigenous in Norway were studied regarding their potential for nutrient removal and resource recovery from wastewater. The nutrient uptake, growth, and cell composition (total proteins and carbohydrates) were monitored under a controlled batch environment for 14 days. Additionally, the fatty acids were analyzed at the end of the study. The fastest nutrient removal was achieved by Lobochlamys segnis F12 that used up NH4+ (28 mg L-1) and PO43- (15 mg L-1) after 4 days. Similar PO43- uptake was achieved by Tetradesmus wisconsinensis H1 while its NH4+ uptake took 2 days longer. Both strains showed a higher specific growth rate (1.1 day-1) than Klebsormidium flaccidum NIVA-CHL80 (0.55 day-1). The highest biomass (1.276 ± 21 mg L-1) and carbohydrates content (40%) were achieved by T. wisconsinensis. K. flaccidum was characterized by superior protein content (53 ± 4%). In terms of total fatty acids production both K. flaccidum and L. segnis were favored (184 ± 6 and 193 ± 12 mg g-1 dry cells), especially with their high polyunsaturated fatty acid content (82 and 67%, respectively). The fatty acids of K. flaccidum consisted mainly C18:2 n-6 (73% of the total). L. segnis had a preferable n3 to n6 ratio (1.3) in their fatty acid profile. The proteins and carbohydrates content changed in all strains depending on the growth stage. Therefore, resource recovery scenarios could be further optimized for a specific cell component production combined with an appropriate strategy for nutrient removal from wastewater.
Abstract
No abstract has been registered
Authors
Seyedbehnam Hashemi Linn Solli Roald Aasen Jacob Joseph Lamb Svein Jarle Horn Kristian Myklebust LienAbstract
No abstract has been registered
Abstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
Claire Coutris Erik J. Joner Cecilie Singdahl-Larsen Ana Catarina Almeida Muhammad Umar Sissel Brit Ranneklev Cecilia AskhamAbstract
Microplastics ending up in nature as a result of end-of-life processes for plastic packaging is a serious environmental concern, and was addressed in the Packnoplast project through sampling at three sites: one biogas facility in Norway and two thermoplastic recycling plants, one in Norway and one in The Netherlands. The amounts of microplastics ending up in soil from biogas digestate was estimated to represent 0.4-2 mg/kg soil per year if 6 t/daa of biogas digestate is used as fertilizer. Food packaging is estimated to represent 75% of this. The amounts of microplastics measured are significant, but too small to affect soil properties even on a time-scale of decades. The risk of adverse effects on soil quality, plant growth or soil organisms seem very low at the current predicted rates of plastic inputs to soil. Since plastics are virtually non-degradable, they are still prone to accumulate in soil, and waste streams recycled to soil need to address and prevent plastic contamination even better than today. Thermoplastic recycling plants are handling large amounts of plastic, and during processes in the plant, microplastics are generated. Concentrations of microplastic particles varied from 7 to 51 particles per lite rin the effluent water from the two plants. Discharges of effluent water are often through the sewer system and/or into a water body. Today regulations regarding discharges of microplastics are missing. Sand filter treatment of the effluent water was a promising treatment technique to remove the microplastics. Background concentrations of microplastics, comparable to pristine areas, were found in blue mussels sampled outside the thermoplastic recycling plant in Norway. Knowledge about the risk imposed by microplastics to the aquatic environment is today not known.