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.
2009
Forfattere
Ole Martin Eklo Randi Bolli Jens Kværner Tore Sveistrup Frauke Hofmeister Eivind Solbakken Nick Jarvis Fredrik Stenemo Eirik Romstad Borghild Glorvigen Tor Anton GurenSammendrag
Contribution of pollution from pesticides is often located to minor areas within a field. Areas with coarse textured materials in the soil profile often represent "hot spots" with high risk of leaching, but also areas with example structured clay soils may be "hot spots". Other areas can be slopes or bottoms in depressions on plateaus were water can be ponded in wet periods or in springtime before the frost has disappeared from the soil profile. If pesticides with high risk of leaching were avoided on these areas, the contribution to groundwater pollution could be reduced extensively. Up to now limited information or tools have been developed for farmers to identify these areas. In a newly completed project, tools for groundwater and surface water protection was developed and evaluated. Three different types of tools have been developed: Topographical maps, risk tables and risk maps. Micro-topographical maps were developed to identify depressions and other vulnerable areas representing high risk of leaching and runoff. Tables of pesticide leaching risk to drainage and groundwater were derived from model simulations in spring cereals and potatoes with the mostly used plant protection strategies on the most common soil types for the areas. A meta-model was used for calculation of pesticide concentrations in groundwater and drainage water, coupled with digital soil maps and presented by Geographical Information Systems (GIS). Farmers from two areas evaluated the usefulness of these tools.Generally the farmers" attitudes to the new tools were positive, but this type of information should be integrated in already existing planning tools at the farm, like fertilizer planning. The project produces large amounts of information and an electronic presentation readily understood and easy to follow is important. In some cases different soil types and topography within the farm represented different risk of leaching. In such cases, it is necessary to easily find pesticides to be used for all areas to avoid time consuming washing and change of equipment.
Forfattere
Ole Martin Eklo Randi Bolli Jens Kværner Tore Sveistrup Frauke Hofmeister Eivind Solbakken Nicolas Jarvis Fredrik Stenemo Eirik Romstad Borghild Glorvigen Tor Anton GurenSammendrag
Det er ikke registrert sammendrag
Forfattere
Odd Finnes Christian UhligSammendrag
Økt pris og mindre tilgang på flis har ført til økende interesse for å bruke torv som strø til husdyr. Torv er et godt strømateriale i følge litteratur og i følge mange husdyrholdere som har gjort egne erfaringer. En viktig fordel med torv er at etterbruken blir enklere. Dette fordi torvblandet gjødsel egner seg mye bedre som plantenæring enn flisblandet gjødsel. For deg som ønsker å prøve torvstrø, er det viktig å ta hensyn til at torv har andre egenskaper enn flis, og at dette har konsekvenser for hvordan strøet skal brukes. Riktig brukt skal torv gi et mykt og tørt underlag som dyra trives på.
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Denitrification is a key ecosystem process which is essential to avoid massive enrichment of nitrate in surface and ground water. A rather narrow group of bacteria are able to carry out denitrification, and they are known to be sensitive to environmentally toxic pollutants like e.g. heavy metals. Since these microorganisms carry out a key ecosystem function, they are strong candidates for testing and monitoring environmental effects of toxic substances likely to reach the soil environment. We conducted a series of experiments where either a pure strain of a denitrifying bacterium (Paracoccus denitrificans) or intact soil microbial communities containing indigenous denitrifiers were subjected to different types of silver nanoparticles (average particle size 20 and 1 nm) at a wide range of concentrations. The results showed that the smallest particles were far more toxic than the larger ones on a mass basis and completely killed off denitrifying bacteria in vitro at concentrations as low as 100 ppb. When soil was present, this concentration had no effect on respiration and even the far more sensitive process of denitrification, measured as production of the gases NO, N2O and N2, was unaffected. Results from experiments that are under way will also be presented. Here threshold levels for inhibition of denitrification by P. denitrificans and intact microbial communities are established for the two types of silver nanoparticles and where toxicity is compared when expressed on a mass basis vs. a surface area basis. Also the sensitivity of the different steps in the denitrification process will be compared and related to corresponding data for dissolved metals. The perspectives for using denitrification impediment as a way to assess ecotoxicity at a functional level will be discussed.
Sammendrag
Silver nanoparticles constitute one of the most common nanomaterials used in consumer products today, and the volumes used are increasing dramatically. Silver is an element known for its acute toxicity to both prokaryotes and a range of aquatic organisms. While ecotoxicity studies on nano-sliver is being studied at species level for some aquatic organisms, corresponding studies on terrestrial organisms are lagging behind. Also, studies targeting functional endpoints rather than purely physiological aspects are lacking. We have compared two types of nano-silver differing in average particle size (1 and 20 nm) with respect to their inhibitory effects on a pure strain of the soil bacterium Paracoccus sp. Which is an efficient denitrifyer capable of transforming NO3 into N2. This process is an important step in the biogeochemical cycling of N, and one that may potentially produce large amounts of the potent green house gas N2O if impeded by environmental pollutants. The results show that nano-silver is highly toxic to denitrifying bacteria and that low amounts severely affect the process of denitrification. Studies using indigenous denitrifying bacterial communities incubated in the presence of different concentrations of nano-silver in soil slurries are under way and will provide data where soil constituents affect the bioavailability nano-silver in a close to realistic exposure scenario. The implications of the relationship between toxicity levels in pure cultures and soil slurries will be discussed regarding the bioavailability of nanoparticles as pollutants in terrestrial environments.
Sammendrag
SUMMARY: Tracers should be used to monitor emissions of leachate from landfills, in order to evaluate environmental pollution. We investigated a selection of parameters commonly found in leachate, in addition to isotopic and radioactive tracers, and their efficiency in tracing leachate in the environment, with emphasis on groundwater. A study at 6 landfills focused on the occurrence of the isotopes 13C and 3H in leachate, surface and groundwater, in relation to the water balance at the sites. The content of heavy carbon (δ13C) in leachate varied between 5.5 to 25.5, in groundwater it reached 4.7 when polluted, and varied between -11.8 to -24.2 when unpolluted, and in surface water from -13.1 to -19.7. Measurements of tritium did not show any systematic trend in the leachate and groundwater samples. Also the elements Fe, B and Cr, and to a minor degree Mn and Zn, showed higher contrasts in leachate/groundwater concentrations. A comparison of the concentrations of tracer compounds with detailed estimation of the water balance at 3 landfills showed that 13C seems to be the most reliable tracer and the factor correlating best with estimates of diffuse losses of leachate to groundwater.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Nadeem Yaqoob Jan Karlsson Benedicte Riber Albrectsen Halvor Solheim Carl Gunnar FossdalSammendrag
In natural conditions plants are continuously exposed to number of pathogens both biotrophs and necrotrophs. To understand their defense response at the transcript level two clones C72 and C23 with differential level of resistance from the SwAsp collection were inoculated with a biotroph (Melampsora magnusiana Wagnar) and necrotroph (Ceratocysis spp.) and compared to wounded and healthy controls. Samples were collected in leaves and areas some distance away from the inoculation site to examine the long distance (systemic) defense responses at day, day3 and day14 post treatments. We performed microarray experiments on the necrotrophic and biothrophic interaction compared with the healthy controls and found that the two clones respond in widely different fashions to the treatments applied. Clone C23 showed almost no response to biotroph and necrotroph inoculations after 24 hours while clone 72 gave a clear defense response to both pathogens. We are now in the process of verifying these results and looking at additional time-points using qRT-PCR.
Forfattere
Eva SkarbøvikSammendrag
Lecture at DRIMON"s (www.drimon.no) student"s workshop in Durres, Albania, September 2009.