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.
2005
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Laboratory incubations with varying O2 and NO3 concentrations were performed with a range of filter materials used in constructed wetlands (CWs). The study included material sampled from functioning CWs as well as raw materials subjected to laboratory pre-incubation. 15N-tracer techniques were used to assess the rates of denitrification versus dissimilatory nitrate reduction to ammonium (DNRA), and the relative role of nitrification versus denitrification in producing N2O. The N2O/(N2+N2O) product ratio was assessed for the different materials. Sand, shell sand, and peat sustained high rates of denitrification. Raw light weight aggregates (LWA) had a very low rate, while in LWA sampled from a functioning CW, the rate was similar to the one found in the other materials. The N2O/(N2+N2O) ratio was very low for sand, shell sand and LWA from functioning CWs, but very high for raw LWA. The ratio was intermediate but variable for peat. The N2O produced by nitrification accounted for a significant percentage of the N2O accumulated during the incubation, but was dependent on the initial oxygen concentration. DNRA was significant only for shell sand taken from a functioning CW, suggesting that the establishment of active DNRA is a slower process than the establishment of a denitrifying flora.
Forfattere
Pål Tore Mørkved Anne Kristine Søvik Bjørn Kløve Lars R. BakkenSammendrag
Laboratory incubations with varying O-2 and NO3 concentrations were performed with a range of filter materials used in constructed wetlands (CWs). The study included material sampled from functioning CWs as well as raw materials subjected to laboratory pre-incubation. N-15-tracer techniques were used to assess the rates of denitrification versus dissimilatory nitrate reduction to ammonium (DNRA), and the relative role of nitrification versus denitrification in producing N2O. The N2O/(N-2 + N2O) product ratio was assessed for the different materials. Sand, shell sand, and peat sustained high rates of denitrification. Raw light-weight aggregates (LWA) had a very low rate, while in LWA sampled from a functioning CW, the rate was similar to the one found in the other materials. The N2O/(N-2 + N2O) ratio was very low for sand, shell sand and LWA from functioning CWs, but very high for raw LWA. The ratio was intermediate but variable for peat The N2O produced by nitrification accounted for a significant percentage of the N2O accumulated during the incubation, but was dependent on the initial oxygen concentration. DNRA was significant only for shell sand taken from a functioning CW, suggesting that the establishment of active DNRA is a slower process than the establishment of a denitrifying flora. Laboratory incubations with varying O-2 and NO3 concentrations were performed with a range of filter materials used in constructed wetlands (CWs). The study included material sampled from functioning CWs as well as raw materials subjected to laboratory pre-incubation. N-15-tracer techniques were used to assess the rates of denitrification versus dissimilatory nitrate reduction to ammonium (DNRA), and the relative role of nitrification versus denitrification in producing N2O. The N2O/(N-2 + N2O) product ratio was assessed for the different materials. Sand, shell sand, and peat sustained high rates of denitrification. Raw light-weight aggregates (LWA) had a very low rate, while in LWA sampled from a functioning CW, the rate was similar to the one found in the other materials. The N2O/(N-2 + N2O) ratio was very low for sand, shell sand and LWA from functioning CWs, but very high for raw LWA. The ratio was intermediate but variable for peat The N2O produced by nitrification accounted for a significant percentage of the N2O accumulated during the incubation, but was dependent on the initial oxygen concentration. DNRA was significant only for shell sand taken from a functioning CW, suggesting that the establishment of active DNRA is a slower process than the establishment of a denitrifying flora.
Forfattere
Pål Tore Mørkved Anne Kristine Søvik Bjørn Kløve Lars R. BakkenSammendrag
Laboratory incubations with varying O2 and NO3 concentrations were performed with a range of filter materials used in constructed wetlands (CWs). The study included material sampled from functioning CWs as well as raw materials subjected to laboratory pre-incubation. 15N-tracer techniques were used to assess the rates of denitrification versus dissimilatory nitrate reduction to ammonium (DNRA), and the relative role of nitrification versus denitrification in producing N2O. The N2O/(N2 þ N2O) product ratio was assessed for the different materials. Sand, shell sand, and peat sustained high rates of denitrification. Raw light-weight aggregates (LWA) had a very low rate, while in LWA sampled from a functioning CW, the rate was similar to the one found in the other materials. The N2O/(N2 þ N2O) ratio was very low for sand, shell sand and LWA from functioning CWs, but very high for raw LWA. The ratio was intermediate but variable for peat. The N2O produced by nitrification accounted for a significant percentage of the N2O accumulated during the incubation, but was dependent on the initial oxygen concentration. DNRA was significant only forshell sand taken from a functioning CW, suggesting that the establishment of active DNRA is a slower process than the establishment of a denitrifying flora.
Forfattere
Trond MæhlumSammendrag
Det er ikke registrert sammendrag
Forfattere
Tore SkrøppaSammendrag
Det er ikke registrert sammendrag
Forfattere
Lars Nesheim Gustav Fystro Olav HarboSammendrag
På tre forsøksfelt i ung eng vart det årleg tilført frå 0 til 5 kg fosfor per dekar i dinatriumhydrogenfosfat (Na2HPO4 x 2H2O). Dette stoffet vart nytta for å unngå samanblanding av verknad av svovel i superfosfat, som er mykje brukt i tidlegare gjødslingsforsøk med fosfor. Målsettinga med feltforsøka var å finne kritiske verdiar for fosforinnhald med omsyn på plantevekst under praktiske tilhøve. Sjølv til dels sterk P-gjødsling førte berre til liten auke i opptak av P i planter, og også til små avlingsutslag, på jord med relativt lite tilgjengeleg fosfor. Slike uventa små utslag medførte at samanhengen mellom plantene sin P-status og avlingsutslag vart dårleg bestemt. Det vart likevel observert ein trend til avlingsreduksjon ved låge P/N-verdiar. Av i alt 10 kg tilført P i gjødsel over to år vart berre 9 % funne att i avlinga.
Forfattere
Olav Lode Kjetil Sola Bente Stensland Bjørn EkebergSammendrag
Feltlysimeterforsøk i jordbær der det er nytta planteverniddel mot ugras, skadedyr og plantesjukdomar er utført på Foss gard i Lier under dagleg leiing av Landbrukets Fagsenter Østlandet. Hovudmålet til prosjektet var å sjå på produksjonssystem som var retta mot miljøvenleg plantevernpraksis og få dokumenter kunnskap om bruk av plantevernmiddel i jord. Artikkelen er konsentrert om restmengdere av plantevernmiddel i grøftevatn og overflatevatn i dyrkingsforsøk der det er nytta svart plast med dryppvatning og mattekultur (halm) der det er bruka vatnspreiar. Det er Pesticidlaboratoriet til Planteforsk som har analysert vatnprøvane.
Forfattere
Kim JohansenSammendrag
I perioden 1997-2004 ble det oftere påvist plantevernmiddelrester i norskdyrkede jordbær enn i importerte. Men de siste årene har trenden snudd. Norskdyrkede jordbær hadde færre påviste plantevernmiddelrester i 2004 enn importerte. Andelen påviste rester over gjeldende grenseverdi er svært lav, og ingen av disse overskridelsene har til nå representert helsefare.
Forfattere
Kim JohansenSammendrag
Den norske jordbærsesongen for 2005 er over og man sammenligner årets resultater med resultatene fra perioden 2000-2004. I år ble det tatt ut færre jordbærprøver enn noen gang, samtidig som det oftere ble påvist plantevernmiddelrester i de norske jordbærene. Nesten 85 % av årets jordbærprøver inneholdt rester av plantevernmidler, ingen av disse overskred gjeldende grenseverdier. Hittil har ingen påviste plantevernmiddelrester i jordbær representert helsefare.