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.
2019
Sammendrag
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Sammendrag
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Forfattere
Perrine Marguerite Fernandez Esther Bloem Andrew Binley Romain S.B.A. Philippe Helen FrenchSammendrag
Assessing redox conditions in soil and groundwater is challenging because redox reactions are oxygen sensitive, hence, destructive sampling methods may provide contact with air and influence the redox state. Furthermore, commonly used redox potential sensors provide only point measurements and are prone to error. This paper assesses whether combining electrical resistivity (ER) and self-potential (SP) measurements can allow the mapping of zones affected by anaerobic degradation. We use ER imaging because anaerobic degradation can release iron and manganese ions, which decreases pore water resistivity, and produces gas, which increases resistivity. Also, electrochemical differences between anaerobic and aerobic zones may create an electron flow, forming a self-potential anomaly. In this laboratory study, with four sand tanks with constant water table heights, time-lapse ER and SP mapped changes in electrical/electron flow properties due to organic contaminant (propylene glycol) degradation. Sampled pore water mapped degradation and water chemistry. When iron and manganese oxides were available, degradation reduced resistivity, because of cation release in pore water. When iron and manganese oxides were unavailable, resistivity increased, plausibly from methane production, which reduced water saturation. To bypass the reactions producing methane and release of metallic cations, a metal pipe was installed in the sand tanks between anaerobic and aerobic zones. The degradation creates an electron surplus at the anaerobic degradation site. The metal pipe allowed electron flow from the anaerobic degradation site to the oxygen-rich near surface. The electrical current sent through the metal pipe formed an SP anomaly observable on the surface of the sand tank. Time-lapse ER demonstrates potential for mapping degradation zones under anaerobic conditions. When an electrical conductor bridges the anaerobic zone with the near surface, the electron flow causes an SP anomaly on the surface. However, electrochemical differences between anaerobic and aerobic zones alone produced no SP signal. Despite their limitations, ER and SP are promising tools for monitoring redox sensitive conditions in unsaturated sandy soils but should not be used in isolation.
Forfattere
Patrick J. Drohan Marianne Bechmann Anthony Buda Faruk Djodjic Donnacha Doody Jonathon M. Duncan Antti Iho Phil Jordan Peter J. Kleinman Richard McDowell Per-Erik Mellander Ian A. Thomas Paul J. A. WithersSammendrag
The evolution of phosphorus (P) management decision support tools (DSTs) and systems (DSS), in support of food and environmental security has been most strongly affected in developed regions by national strategies (i) to optimize levels of plant available P in agricultural soils, and (ii) to mitigate P runoff to water bodies. In the United States, Western Europe, and New Zealand, combinations of regulatory and voluntary strategies, sometimes backed by economic incentives, have often been driven by reactive legislation to protect water bodies. Farmer‐specific DSSs, either based on modeling of P transfer source and transport mechanisms, or when coupled with farm‐specific information or local knowledge, have typically guided best practices, education, and implementation, yet applying DSSs in data poor catchments and/or where user adoption is poor hampers the effectiveness of these systems. Recent developments focused on integrated digital mapping of hydrologically sensitive areas and critical source areas, sometimes using real‐time data and weather forecasting, have rapidly advanced runoff modeling and education. Advances in technology related to monitoring, imaging, sensors, remote sensing, and analytical instrumentation will facilitate the development of DSSs that can predict heterogeneity over wider geographical areas. However, significant challenges remain in developing DSSs that incorporate “big data” in a format that is acceptable to users, and that adequately accounts for catchment variability, farming systems, and farmer behavior. Future efforts will undoubtedly focus on improving efficiency and conserving phosphate rock reserves in the face of future scarcity or prohibitive cost. Most importantly, the principles reviewed here are critical for sustainable agriculture.
Forfattere
Sofie Hellsten Tommy Dalgaard Katri Rankinen Kjetil Tørseth Lars Bakken Marianne Bechmann Airi Kulmala Filip Moldan Stina Olofsson Kristoffer Piil Kajsa Pira Eila TurtolaSammendrag
During the past twenty years, the Nordic countries (Denmark, Sweden, Finland and Norway) have introduced a range of measures to reduce losses of nitrogen (N) to air and to aquatic environment by leaching and runoff. However, the agricultural sector is still an important N source to the environment, and projections indicate relatively small emission reductions in the coming years. The four Nordic countries have different priorities and strategies regarding agricultural N flows and mitigation measures, and therefore they are facing different challenges and barriers. In Norway farm subsidies are used to encourage measures, but these are mainly focused on phosphorus (P). In contrast, Denmark targets N and uses control regulations to reduce losses. In Sweden and Finland, both voluntary actions combined with subsidies help to mitigate both N and P. The aim of this study was to compare the present situation pertaining to agricultural N in the Nordic countries as well as to provide recommendations for policy instruments to achieve cost effective abatement of reactive N from agriculture in the Nordic countries, and to provide guidance to other countries. To further reduce N losses from agriculture, the four countries will have to continue to take different routes. In particular, some countries will need new actions if 2020 and 2030 National Emissions Ceilings Directive (NECD) targets are to be met. Many options are possible, including voluntary action, regulation, taxation and subsidies, but the difficulty is finding the right balance between these policy options for each country. The governments in the Nordic countries should put more attention to the NECD and consult with relevant stakeholders, researchers and farmer's associations on which measures to prioritize to achieve these goals on time. It is important to pick remaining low hanging fruits through use of the most cost effective mitigation measures. We suggest that N application rate and its timing should be in accordance with the crop need and carrying capacity of environmental recipients. Also, the choice of application technology can further reduce the risk of N losses into air and waters. This may require more region-specific solutions and knowledge-based support with tailored information in combination with further targeted subsidies or regulations.
Sammendrag
Redusert og endret jordarbeiding har vært et av de viktigste tiltakene mot erosjon og tap av næringsstoffer fra jordbruksarealer siden begynnelsen på 1990-tallet. Redusert jordarbeiding betyr bare harving i stedet for pløying, mens endret jordarbeiding betyr pløying om våren i stedet for høsten. Avrenningsforsøk som startet på 1980-tallet viser stor effekten av redusert og endret jordarbeiding på erosjon og næringsstofftap på forholdsvis bratte jordbruksarealer. Det eksisterer derimot kun få undersøkelser av jordarbeidingseffekter på arealer med liten helling, på tross av at slike arealer utgjør størsteparten av jordbruksarealene der det dyrkes korn.
Sammendrag
Nitrogen (N) losses from agricultural areas, especially into drinking water and marine environments, attract substantial attention from governments and scientists. This study analysed nitrogen loss from runoff water using long-term monitoring data (1994–2016) from the Skuterud catchment in southeastern Norway and the Naurstad catchment in northern Norway. Precipitation and runoff were lower in the Skuterud catchment than in the Naurstad catchment. However, in the Skuterud catchment, the annual total N (TN) losses ranged from 27 to 68 kg hm−2. High precipitation (1247 mm) in the Naurstad catchment resulted in substantial runoff water (1108 mm) but relatively low total TN losses ranged from 17 to 35 kg hm−2. The proportion of nitrate losses to TN loss was 51–86% and 28–50% in the Skuterud and Naurstad catchments, respectively. Furthermore, the monthly average TN concentrations and nitrate losses had two peaks, in April–May and October, in the Skuterud catchment; however, no significant fluctuations were found in the Naurstad catchment. The contributions of N and runoff water to TN and nitrate losses were calculated using multiple linear regression, and runoff water was the major contributor to TN loss in both catchments. Runoff water was the main factor in the Skuterud catchment, and the nitrate-N concentration was the main factor in the Naurstad catchment.
Sammendrag
Formålet med dette prosjketet var å kartlegge risiko for vannforurensning i forbindelse med utvask av fjørfehus. Det er her fokus på næringsstoffer, men det kan også bidra til å belyse risiko for utslipp av vaskemidler til vassdrag. Prosjektet omfatter en spørreundersøkelse blant fjørfeprodusenter i Rogaland vedrørende rengjøring, vask og avløpsløsning; en kort gjennomgang av praksis andre steder og forslag til videre undersøkelser. Spørreundersøkelsen viser at risiko for forurensning varierer mye fra produsent til produsent. Den totale risikoen for utslipp til resipient fra et fjørfehus må vurderes samlet ut fra antall vaskinger per år, type innredning, omfang av rengjøring (fjerning av strø og gjødsel før vasking) og avløpsløsning hos produsenten....
Sammendrag
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Sammendrag
Prosjektet innhentet informasjon om dagens erfaringer med tiltak for skråningsstabilisering, felles praksis og trender i Norge. Spørreskjema ble utarbeidet av en tverrfaglig forskningsgruppe og inneholdt følgende tema; hydrologiske forhold, tekniske løsninger, vegetasjonsvalg og jord/geologiske forhold. Det ble sendt til relevante kontaktpersoner i Statens vegvesen (SVV), Bane NOR og Norges Vann- og energidirektorat (NVE). Besvarelsene fra etatene er systematisert og sammenstilt i denne rapporten.