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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.

2022

Sammendrag

Sustainable phosphorus use is essential in golf course management to prevent eutrophication and overconsumption. The study aimed to investigate if phosphorus fertilization can be reduced without negative effects on turf quality. We compared two P fertilization recommendations based on soil analyses, one based on the annual nitrogen rate, and a zero-P control. The recommendations were the “minimum level of sustainable nutrition” (MLSN), which aims to keep treatment soil levels above 18 mg P kg–1 dry soil (Mehlich-3); the “sufficiency level of available nutrition” (SLAN), in which the threshold for excluding P fertilization is >54 mg P kg–1 dry soil (Mehlich-3); and “Scandinavian precision fertilization” (SPF), which recommends applying P at 12% of the annual N rate. The treatments were compared via monthly assessments of turf quality and the coverage of sown species and annual bluegrass (Poa annua L.) from 2017 to 2020 on five golf courses from Germany, Sweden, China, Norway, and the Netherlands. MLSN and SPF significantly reduced soil P at all sites compared with SLAN recommendations. Turf quality showed no significant differences. The results from the mixed creeping bentgrass (Agrostis stolonifera L.)–annual bluegrass green showed a 2 to 4% increase in annual bluegrass coverage with P fertilization over the zero-P treatments. The MLSN guideline is recommended for sustainable P fertilization on established greens with low P sorption capacity under diverse climatic and management conditions. The SPF may result in application of excess P to soils with high Mehlich-3 values, as soil analyses are not considered.

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Key words: VKM, risk assessment, Norwegian Scientific Committee for Food and Environment, Norwegian Environment Agency, potential toxic elements (PTEs), fertiliser, soil improver, fertiliser products, growing media, circular economy, circulation of organic fertilisers, arsenic (As), cadmium (Cd), chromium Cr(tot) (Cr(III) and Cr(VI)), copper (Cu), lead (Pb), mercury (Hg), nickel (Ni), zinc (Zn). Background and purpose of the report The potentially toxic elements (PTE) arsenic (As), cadmium (Cd), chromium Cr(tot) (Cr(III) and Cr(VI)), copper (Cu), lead (Pb), mercury (Hg), nickel (Ni) and zinc (Zn) occur as ingredients or contaminants in many fertilisers, soil improvers, engineered soil and growing media. Application of these fertiliser products might represent a risk towards the environment, farm animals and humans, particularly when applied annually over several years. The present risk assessment evaluates the application of selected fertilisers according to certain scenarios for representative Norwegian agricultural areas, from Troms in the North to Ås in Southeastern and Time in Southwestern Norway, with different soil properties, precipitation and PTE concentration in present agricultural soil. There is an increasing trend to produce locally (e.g. in urban farming) and home-grown vegetables that are cultivated in engineered soil and growth media. The maximum levels (MLs) set for PTEs in different organic fertilisers, engineered soil and growing media for use in urban farming, home growing and the cultivation of vegetables and garden fruits, and a set of MLs also for application in agricultural cultivation of crops, have been evaluated. Environmental fate processes and the transfer of PTEs have been modelled and the environmental risks for terrestrial and aquatic organisms, including from secondary poisoning have been estimated. Potential risks to humans and farmed animals by increased exposure to PTEs from, respectively, agriculturally produced crops, vegetables cultivated at home and urban farming or forage and grazing have been evaluated. The recycling of nutrients is urgently needed to achieve circular economy, but the derived sustainable products have to be safe, which requires the introduction of and adherence to science-based maximum levels of unwanted substances (e.g. pollutants). This assessment evaluates consequences of the application of different fertiliser products: mineral P fertilisers, manure from cattle, pig, poultry and horse, fish sludge, digestates and sewage sludge - in order to identify PTE sources with potential environmental, animal and human health risks, and to evaluate the appropriateness of the current MLs regarding different applications of organic-based fertilisers, engineered soil and growing media at present, and in a 100-year perspective. Approach and methods applied The approach for environmental and health risk assessments builds on previous work performed for hazardous substances in soil (e.g. VKM 2019, VKM 2014, VKM, 2009, Six and Smolders, 2014). Concentrations of PTEs in soil over time were calculated using a mass balance model, which considers the input by atmospheric deposition, use of fertilisers and soil improvers, as well as loss by leaching, run-off and plant uptake. The resulting first-order differential equation was solved analytically and implemented into Excel®. Run-off and loss by leaching were estimated from data on precipitation, infiltrating fraction and run-off fraction of the water under consideration of the distribution coefficient Kd for the concentration ratio of bulk soil-to-water. This Kd value takes aging sufficiently into account and is thus more realistic than those derived from batch tests. The Kd was estimated separately for each region using established regression equations, with soil pH, organic matter content and clay content as predictors. ...........

2021

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Sammendrag

Bicarbonate was evaluated as an alternative carbon source for a green microalga, Tetradesmus wisconsinensis, isolated from Lake Norsjø in Norway. Photosynthesis, growth, and lipid production were studied using four inorganic carbon regimes: (1) aeration only, (2) 20 mM NaHCO3, (3) 5% (v/v) CO2 gas, and (4) combination of 20 mM NaHCO3 and 5% CO2. Variable chlorophyll a fluorescence analysis revealed that the bicarbonate treatment supported effective photosynthesis, while the CO2 treatment led to inefficient photosynthetic activity with a PSII maximum quantum yield as low as 0.31. Conversely, bicarbonate and CO2 treatments gave similar biomass and fatty acid production. The maximum growth rate, the final cell dry weight, and total fatty acids under the bicarbonate-only treatment were 0.33 (± 0.06) day−1, 673 (± 124) mg L−1 and 75 (± 5) mg g−1 dry biomass, respectively. The most abundant fatty acid components were α-linolenic acid and polyunsaturated fatty acids constituting 69% of the total fatty acids. The fatty acid profile eventuated in unsuitable biodiesel fuel properties such as high degree of unsaturation and low cetane number; however, it would be relevant for food and feed applications. We concluded that bicarbonate could give healthy growth and comparative product yields as CO2.

Sammendrag

The aim of this study was to contribute to closing global phosphorus (P) cycles by investigating and explaining the effect of fish sludge (feed residues and faeces of farmed fish) and manure solids as P fertiliser. Phosphorus quality in 14 filtered and/or dried, composted, separated or pyrolysed products based on fish sludge or cattle or swine manure was studied by sequential chemical fractionation and in two two-year growth trials, a pot experiment with barley (Hordeum vulgare) and a field experiment with spring wheat (Triticum aestivum). In fish sludge, P was mainly solubilised in the HCl fraction (66 ± 10%), commonly being associated with slowly soluble calcium phosphates, and mean relative agronomic efficiency (RAE) of fish sludge products during the first year of the pot experiment was only 47 ± 24%. Low immediate P availability was not compensated for during the second year. Thus efforts are needed to optimise the P effects if fish sludge is to be transformed from a waste into a valuable fertiliser. In manure solids, P was mainly soluble in H2O and 0.5 M NaHCO3 (72 ± 14%), commonly being associated with plant-available P, and mean RAE during the first year of the pot experiment was 77 ± 19%. Biochars based on fish sludge or manure had low concentrations of soluble P and low P fertilisation effects, confirming that treatment processes other than pyrolysis should be chosen for P-rich waste resources to allow efficient P recycling. The field experiment supported the results of the pot experiment, but provided little additional information.

Sammendrag

Fosforkvaliteten i 15 organiske gjødselprodukter ble undersøkt med hjelp av kjemiske analysemetoder, og i potte- og feltforsøk. Husdyrgjødsel viste bedre fosforeffekt enn fiskeslam og biokull. Struvitt viste også god effekt sammenlignet med mineralfosfor. Fosfor i de organiske produktene forelå hovedsakelig som ulike kalsiumfosfater, og det var godt samsvar mellom fosforkvaliteten og opptak i planter. Andelen bikarbonat (NaHCO3)-løselig fosfor i organiske gjødselprodukter kan brukes som indikator på fosforkvaliteten (lav, medium, høy) men kan ikke brukes for nøyaktig predikering.

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Sammendrag

Produksjon av biogass er et viktig tiltak både for redusering av klimagassutslipp og resirkulering av næringsstoffer. Det kan også være en inntektskilde for bønder og skaper positive økonomiske ringvirkninger i distrikta. Dette prosjektet tok utgangpunkt i to biogassanlegg under planlegging eller utbygging og substratene som er tilgjengelig i nærområdet: meierislam, ullvaskevann, og grillfett. Det ble gjennomført labskala forsøk på disse substratene i kombinasjon med husdyrgjødsel under ulike forhold. Det ble også gjort en økonomisk vurdering av biogassanlegg på ulike størrelser som tar imot disse substratene, og av samlokalisering av et ullvaskeri i kombinasjon med et biogassanlegg og andre bedrifter på Tingvoll, et tettsted i Møre og Romsdal. Samarbeidspartnerne i prosjektet var NIBIO, NORSØK, Tingvoll Ull, Hustadvika Biokraft, Tine Elnesvågen, og Statsforvalteren i Møre og Romsdal. Resultatene fra biogassforsøket viser at ullvaskevann og meierislam gav generelt lavere gassutbytter enn grillfett, både i biometanpotensiale test og i kontinuerlige reaktorer. Noe av forklaringen på lavt metanutbytte kan være at både ullvaskevann og meierislam brukt i denne testen hadde høyt vanninnhold (tørrstoffinnhold rundt 1%), var lite energikonsentrert, og hadde relativt lave fettsyrekonsentrasjoner. En annen forklaring kan være synergistisk inhibering grunnet kombinasjonen av enkelte fettsyrer og ammoniakk. Det ble målt høyest metanutbytte fra ullvaskevann og meierislam (henholdsvis 200-250 og 150 – 200 mL metan / g VS) når mengden av disse substratene tilsatt reaktorene var 150-200 mL og på driftstemperatur 41 og 55 C. Maksimum utbytte til grillfett var 300 mL metan /g VS når det var tilsatt 300 mL til reaktoren. Økt driftstemperatur vil gi økt enzymaktivitet og nedbrytningsgrad med påfølgende økt metanutbytte i biogassreaktorer med lav belastning. Dette er sannsynligvis noe av forklaringen på økt metanutbytte med forhøyet temperatur i reaktorene. Meierislammet er lett nedbrytbart og kan gi betydelig gassproduksjon hvis det er mer konsentrert, og har næringsstoffinnhold som kan gi bedre biorestkvalitet. Ullvaskevann og meierislam kan også vurderes behandlet i andre typer reaktorer som for eksempel UASB eller biofilmreaktorer. Grillfett fra kylling gir økt gassproduksjon, men har ikke særlig innhold av næringsstoffer og kan være utfordrende for anlegget både prosessmessig og mekanisk ved avleiring av fett. Ullvasking krever mye vann og varme. Det finnes flere tiltak for å effektivisere prosessen, som gjenvinning av gråvann og varme. Lønnsomhetsberegninger bekrefter at ullvaskevann nok må befinne seg i nærheten av et biogassanlegg slik at det kan fungere som prosessvann (lavere gate-fee), og at eventuelt N i vaskevannet kan gi merverdi til bioresten for at det skal bli en god løsning både for substrateier og anleggseier. Plassering av et ullvaskeri på Tingvoll har sine fordeler, men også sine utfordringer. Tilgang til rimelig varme i begrensede perioder, gjenvinning av vaskevann og varme, omsetning av avløpsvann direkte som gjødsel eller substrat i et biogassanlegg, omsetning av lanolinen, og samarbeid om vakt og drift er avgjørende faktorer for at det skal være lønnsomt å plassere et ullvaskeri på Tingvoll. Alternative løsninger til vasking med uttak av lanolin er interessant, og Tingvoll Ull planlegger et eget prosjekt som ser på en slik mulighet.

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Sammendrag

Power-to-methane technology is a promising solution to facilitate the use of excess variable renewable energy for biomethane production. In this approach, hydrogen produced via electrolysis is used to upgrade raw biogas, which can be subsequently used as fuel or stored in the gas grid. Ex-situ biomethanation is an emerging technology that could potentially replace conventional energy-intensive biogas upgrading methods and allow CO2 utilization for biomethane production. This work provides a comprehensive overview on the current status of ex-situ biomethanation with particular attention to trickle bed reactor. The review includes description of ex-situ biomethanation and summarizes previous works on this topic. The key elements related to operational conditions, efficiency, and microbiology of ex-situ biomethanation using trickle bed reactor are described here. Additionally, the review highlights the technical and economic issues that have to be addressed for future development and large-scale implementation of ex-situ biomethanation.