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.
2006
Sammendrag
Effects of composting on survival and reproduction of the potato cyst nematode (PCN) Globodera rostochiensis were investigated in 150-liter pilot scale reactors. Small bags containing cysts of PCN were incubated in organic waste and composted for 8, 15 or 29 days. Temperatures in the areas close to the cyst bags were monitored. Survival, measured by hatching, was reduced by 99.9% already after 8 days of composting and at 29 days no hatching was recorded. A few eggs, however, still hatched after being composted for 15 days and exposed to temperatures higher than 60°C for several days. Maximal temperatures and thermal exposure time as such could not explain the hatching pattern of PCN, so other factors are likely to be involved in causing lethality. PCN failed to reproduce after 8 days of composting with temperatures reaching a minimum of 50°C during the period. Hence, eight days of composting where all material have reached a temperature of minimum 50°C during the period, could be regarded as a satisfactory method for sanitation of PCN.
Forfattere
L.E. Sverdrup Thomas Hartnik E. Mariussen J. JensenSammendrag
Halogenated flame retardants have a high sorption affinity to particles, making soils and sediments important sinks. Here, three of the most commonly used flame retardants have been tested for sub-lethal toxicity towards soil nitrifying bacteria, a terrestrial plant (seed emergence and growth of the red clover, Trifolium pratense), and a soil invertebrate (survival and reproduction of Enchytraeus crypticus). Tetrabromobisphenol A (TBBPA) was quite toxic to enchytraeids, with significant effects on reproduction detected already at the 10 mg kg1 exposure level (EC10 = 2.7 mg kg1). In contrast, decabromodiphenyl ether (DeBDE) was not toxic at all, and short-chain chloroparaffins (CP10"13) only affected soil nitrifying bacteria at the highest test concentration (EC10 = 570 mg kg1). Exposure concentrations were verified by chemical analysis for TBBPA and DeBDE, but not for CP10"13, as a reliable method was not available. Based on the generated data, a PNEC for soil organisms can be estimated at 0.3 mg kg1 for TBBPA and 57 mg kg1 for short-chain chloroparaffins. No PNEC could be estimated for DeBDE. Measurements of TBBPA in soil are not available, but measured concentrations in Swedish sludge are all lower than the estimated threshold value for biological effects in soil.
Forfattere
Yngve RekdalSammendrag
På oppdrag fra Hedemarken og Sør-Østerdal jordskifterett er det i denne rapporten gitt ei vurdering av utmarksbeite for området Nordaberget/Blåenga nordvest i Våler kommune i Hedmark. Vurderingene omfatter beitekvalitet og -kapasitet og er gjort eiendomsvis for fire eiendommer: Nordaberget, Gjerdrum øst, Gjerdrum vest og Rud. Rapporten bygger på data fra skogtakst for området, markslag i Økonomisk kartverk, ortofoto, satellittfoto og erfaring fra lignende oppdrag i midtre deler av Hedmark. Området er ikke synfart. Området Nordaberget/Blåenga er 85 800 dekar stort. 3000 dekar av dette er vann. Mye av arealet ligger mellom 300 og 500 m o.h., med topper over 500 m. Skogarealet består stort sett av barskog. Gran er dominerende treslag og finnes i lier og på anna areal med godt jorddekke og moderat til frisk vannforsyning. Blåbærskog er dominerende vegetasjonstype. I bratte parti finnes frodigere skog av småbregne-, lågurt- eller høgstaudetype. Furuskog finnes på skrinne topper og på fastmarkskjøler i myrområder. 64% av Nordaberget/Blåenga er nyttbart beiteareal. Samla kan området settes til verdien godt beite som gir 65 saueenheter per km² nyttbart beiteareal. Eiendommene har litt variasjon og beiteverdien øker fra sør mot nord. Området har totalt kapasitet til mellom 3200 og 3900 saueenheter. Tallet forutsetter at beitet utnyttes jamt og at det drives skogsdrift i området. Tallet forutsetter også en blanding av sau og storfe i og med at deler av myrarealet som bare vil utnyttes av storfe, er regna inn i nyttbart beiteareal. Korrigert for sannsynlig fôruttak av elg bør sauetallet reduseres med 8% til 2900 – 3600 saueenheter.
Forfattere
Anne Kristine Søvik Bjørn Kløve Kaisa Haikkinen J. Augustin Jari Huttunen J.M. Necki Satu Karjalainen Anu Liikanen Ülo Mander Markku Puustinen S. Teiter P. WachniewSammendrag
The potential atmospheric impact of constructed wetlands (CWs) should be examined as there is a worldwide increase in the development of these systems. Fluxes of N2O, CH4, and CO2 have been measured from CWs in Estonia, Finland, Norway, and Poland during winter and summer in horizontal and vertical subsurface flow (HSSF and VSSF), free surface water (FSW), and overland and groundwater flow (OGF) wetlands. The fluxes of N2O-N, CH4-C, and CO2-C ranged from "2.1 to 1000, "32 to 38 000, and "840 to 93 000 mg m"2 d"1, respectively. Emissions of N2O and CH4 were significantly higher during summer than during winter. The VSSF wetlands had the highest fluxes of N2O during both summer and winter. Methane emissions were highest from the FSW wetlands during wintertime. In the HSSF wetlands, the emissions of N2O and CH4 were in general highest in the inlet section. The vegetated ponds in the FSW wetlands released more N2O than the non-vegetated ponds. The global warming potential (GWP), summarizing the mean N2O and CH4 emissions, ranged from 5700 to 26000 and 830 to 5100 mg CO2-equivalents m"2 d"1 for the four CW types in summer and winter, respectively. The wintertime GWP was 8.5-89.5% of the corresponding summertime GWP, which highlights the importance of the cold season in the annual greenhouse gas release from north temperate and boreal CWs. However, due to their generally small area North European CWs were suggested to represent only a minor source for atmospheric N2O and CH4.
Forfattere
Ingrid Holtsmark Dimitris Mantzilas Vincent Eijsink May Bente BrurbergSammendrag
Members of the actinomycete genus Clavibacter are known to produce antimicrobial compounds, but so far none of these compounds has been purified and characterized. We have isolated an antimicrobial peptide, michiganin A, from the tomato pathogen Clavibacter michiganensis subsp. michiganensis, using ammonium sulfate precipitation followed by cation-exchange and reversed-phase chromatography steps. Upon chemical derivatization of putative dehydrated amino acids and lanthionine bridges by alkaline ethanethiol, Edman degradation yielded sequence information that proved to be sufficient for cloning of the gene by a genome-walking strategy. The mature unmodified peptide consists of 21 amino acids, SSSGWLCTLTIECGTIICACR. All of the threonine residues undergo dehydration, and three of them interact with cysteines via thioether bonds to form methyllanthionine bridges. Michiganin A resembles actagardine, a type B lantibiotic with a known three-dimensional structure, produced by Actinoplanes liguriae, which is a filamentous actinomycete. The DNA sequence of the gene showed that the michiganin A precursor contains an unusual putative signal peptide with no similarity to well-known secretion signals and only very limited similarity to the (only two) available leader peptides of other type B lantibiotics. Michiganin A inhibits the growth of Clavibacter michiganensis subsp. sepedonicus, the causal agent of ring rot of potatoes, with MICs in the low nanomolar range. Thus, michiganin A may have some potential in biological control of potato ring rot.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Christian UhligSammendrag
Soil erosion control mats generally prevent erosion and enhance soil physical conditions for plant growth. However, commonly used mat materials as coconut fiber and synthetic fabrics are naturally poor in plant nutrients and thus do not improve soil chemical properties. The main aim of this paper is to propose alternative materials for the production of erosion control mats, which mutually improves soil physical and chemical properties. Theoretically, the perfect material for soil erosion control mats combines all essential physical properties, e.g. physical stability, together with beneficial biological and chemical properties, like adequate bio-degradability and plant nutrient release. Furthermore, mat material, which promote soil organic matter (SOM) enrichment and thus soil development, would be favourable. From the economically and practically point of view, mat material should be cheap, available and workable. According to a literature review and practical experiences organic material derived from Epilobium angustifolium (fireweed) fulfil several of the above listed requirements. Furthermore, fireweed widely appears in early successional phases within several boreal and temperate vegetation types, and can consequently be considered a natural component for revegetation and soil development of these ecosystems. So far no allelopathic effects of its plant residues have been reported. Additionally benefits by using fireweed for the production of soil erosion control mats may derive from its ability to effectively disperse vegetative and generatively. Root cuttings as small as 2.5 x 1.5 mm were capable of producing adventitious buds and single plants might yield as many as 80,000 seeds per year with a germination rate of up to 100 % (Jobidon 1986 and literature within). Thus, the use of entire fireweed plants, including roots and matured seeds for the production of soil erosion control mats may indirectly support revegetation efforts of disturbed sites. According to Broderick (1990) and Mitich (1999) fireweed may prove to be a good species for artificial revegetation and land rehabilitation projects.
Forfattere
Anne S. Halstensen Karl-Christian Nordby Sonja Klemsdal Oleif Elen Per Erik Clasen Weijnand EduardSammendrag
Trichothecenes are immunosuppressive mycotoxins produced mainly by Fusarium spp. and often are detected as natural contaminants of grain and other agricultural products. Exposure to trichothecenes through inhalation during grain work may represent possible health risks for grain farmers. We aimed, therefore, to investigate the level of Fusarium spp. and trichothecenes in settled grain dust collected during work on 92 Norwegian farms. Mycotoxins were determined by gas chromatography-mass spectrometry, whereas the Fusarium spp. were identified and quantified both by species-specific semiquantitative polymerase chain reaction (PCR) and by cultivation. All potential trichothecene-producing molds in the grain dust were quantified using a PCR assay specific for tri5, the gene coding for trichodiene synthase that catalyzes the first step in the trichothecene biosynthesis. We performed correlation analysis between mold-DNA and mycotoxins to assess whether the PCR-detected DNA could be used as indicators of the mycotoxins. The methodological problem of detecting small amounts of airborne mycotoxins during grain work may then be avoided. Whereas the trichothecene-producing Fusarium species in grain dust could not be identified or quantified to a sufficient extent by cultivation, all investigated Fusarium spp. could be specifically detected by PCR and quantified from the DNA agarose gel band intensities. Furthermore, we observed a strong correlation between the trichothecenes HT-2 toxin (HT-2) or T-2 toxin (T-2) and DNA specific for tri5 (r = 0.68 for HT-2 and r = 0.50 for T-2; p < 0.001), F. langsethiae (r = 0.77 for HT-2 and r = 0.59 for T-2; p < 0.001), or F. poae (r = 0.41 for HT-2 and r = 0.35 for T-2; p < 0.001). However, only a moderate correlation was observed between the trichothecene deoxynivalenol ( DON) and the combination of its producers, F. culmorum and F. graminearum (r = 0.24, p = 0.02), and no significant correlation was observed between DON and tri5. PCR clearly improved the detection of toxigenic Fusaria as potential sources of health risks for farmers inhaling grain dust during work, but the use of Fusarium-DNA as indicators for trichothecenes should be used cautiously.
Forfattere
Ragnar Eltun Thor Johannes Rogneby Hanne HombSammendrag
Fôrvikker og havre er aktuelle vekster i grønngjødslingsblandinger for å gi rask dekking og god konkurranse mot ugraset. Perserkløver og legesteinskløver ser ikke ut til å ha spesielle fordeler framfor rødkløver. Raigras fanger opp en del nitrogen om høsten, men det ble ikke funnet noen langtidseffekt av dette. Grønngjødslingsveksten gav god avling av etterfølgende korn, men artssammensetningen var ikke avgjørende for forgrødeeffekten. Forsøkene gav således ikke noe klart svar på hvilke blandinger som gir best forgrødeeffekt, men ut fra en helhetsvurdering kan en anbefale følgende vekster i en grønngjødselblanding til korn: havre, fôrvikker, rødkløver og raigras.
Forfattere
Tor Gunnar Vågen Markus G Walsh Keith D. ShepherdSammendrag
The impacts of human land use in the highlands of Madagascar are often equated with land degradation and decreasing soil fertility. The practice most often focused on is deforestation through slash-and-burn cultivation (tavy), and shifting cultivators are often portrayed as being ignorant, poverty-stricken peasants felling trees for fields and food. However, there is uncertainty whether soil degradation is related to recent tavy or earlier forest clearance, and whether some highland areas were ever forested. In this paper we use stable isotopes (!13C) and diffuse reflectance spectroscopy (DRS) to study the impacts of deforestation and various other land use changes on ecosystem properties, soil organic carbon (SOC) dynamics and soil quality (fertility) in the highlands of Madagascar. Land cover transitions (between C3 and C4 systems) are defined and quantified in the study area. Historical land use had greater effect on soil organic carbon concentrations than current land use, with cultivated areas previously under C3 and C4 systems having 37.3 and 14.8 g SOC kg"1, respectively. Grasslands previously under C3 had approximately 124% more SOC than grasslands previously under C4, while SOC concentrations were 65.3 and 54.9 g C kg"1 under natural forest and in mixed fallow systems, respectively. A soil fertility index developed for the study area based on diagnostic soil spectra was compared with findings related to SOC dynamics and land use change.