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.
2007
Authors
Britt I.F. HenriksenAbstract
I økologisk geitehald er det krav om fast liggeareal og minst 1,5 m2 areal per geit og 0,35 m2 per kje. Oppføring av liggehyller til geit kan være med på å imøtekomme desse krava.
Authors
Lars Tørres Havstad Trygve S. AamlidAbstract
Tiller demography and contribution to seed yield were studied in first year seed crops of Bromus inermis `Løfar" and Festuca pratensis `Salten" planted on different dates and with increasing plant densities (A: 15 or 18 Jun / 11 plants m-2, B: 15 or 30 July / 44 plants m-2, C: 15 August or 10 September /178 plants m-2) in field trials at Landvik, SE Norway, in 1998 and 1999. While the total tiller population in most crops increased until seed harvest, it decreased during panicle elongation in crops of Bromus inermis and Festuca pratensis that had reached 2000 and 3500 tillers m-2 in early spring, respectively. Except for the fact that many of the primary tillers of Bromus inermis died after producing barren stems, tillers formed in August and September had the greatest chance of becoming reproductive and produced the longest culms with the heaviest inflorescences in both species. Most tillers produced in winter or early spring either remained vegetative or died, but spring-emerging tillers contributed up to 30% of the total seed yield in early-established, low-density crops of Festuca pratensis. The results are discussed in relation to former papers suggesting that inter-tiller transfer of flower induction stimuli is possible in some perennial grasses. It is concluded that tillers produced in winter and spring contribute more to seed yield in Festuca pratensis than in Bromus inermis.
Authors
Therese With Berge Haldor Fykse Are H. AastveitAbstract
A major obstacle to patch spraying of broad-leaved weeds in cereals is a cost-effective method to assess within-field heterogeneity of the weed population. One method could be a camera mounted in front of the spraying vehicle, online image analysis, and field sprayer shifting between "on" and "off" as the predefined weed damage threshold level is reached. Because such a camera will capture a very limited area (
Authors
Bjørn Molteberg Frank EngerAbstract
Gras til grøntanlegg har tidligere vært en del av den offisielle verdiprøvingen av plantesorter her i landet. Det har vært en forvaltningsoppgave som Bioforsk Øst Apelsvoll (tidligere Planteforsk Apelsvoll forskingssenter) har gjennomført på oppdrag fra og etter retningslinjer gitt av Mattilsynet (tidligere Landbrukstilsynet) ( http://www.mattilsynet.no/planter/sortsgodkjenning/offisiell_registrering_av_plantesorter_10655 ) Fra og med 1. november 2004 ble det norske regelverket endret i overensstemmelse med direktivene i EØS-avtalen og ESA (EFTAs overvåkingsorgan). Endringen førte til at det nå ikke lenger stilles krav om verdiprøving av grassorter som ikke er beregnet til bruk som fôrvekster, dvs. for grassorter kun til bruk i grøntanlegg. Mattilsynet har derfor vedtatt å avvikle den offisielle verdiprøvingen av gras til grøntanlegg, men vil foreløpig opprettholde sortslisten for disse sortene. I 2003 ble det startet en ny 4-årig forsøksserie i verdiprøving av gras til grøntanlegg. I enighet mellom Bioforsk og Mattilsynet ble det vedtatt at denne prøvingen skulle delvis gå som planlagt ut 2006, til tross for total fjerning av krav om verdiprøving av gras til grøntanlegg i regelverket. Denne "reduserte" prøvingen i gras til grøntanlegg fra 2003-2006 blir derfor den siste prøvingen i offentlig regi. Prøvingen er nå blitt erstattet av ei fellesnordisk veiledningsprøving (www.scanturf.org). På sikt vil trolig også denne igjen gå inn i en felles europeisk prøving. Hovedmålet med den offisielle verdiprøvingen har vært å framskaffe forsøksresultater som skulle danne grunnlaget for godkjenning av nye sorter for opptak på norsk sortsliste. Behov for resultater og anbefalinger fra verdiprøvingen 2003-2006 vil etter de nye reglene, som nevnt ovenfor, ikke lenger være nødvendig for sortslisteopptak. Alle DUS-testete sorter fra denne prøvingen vil komme på listen, hvis ønskelig fra sortseier. Som en avslutning på prøvingen og forsøksserien velges det likevel å presentere forsøksresultatene med anbefalinger. Her blir totalsammendraget for hele forsøksperioden presentert, både i tekst og tabellform. Forsøkene bestod av 5 arter og 41 sorter, hvorav 24 var under prøving og 17 var målesorter. Av de 24 sortene som var under prøving er 20 anbefalt for plen eller grasbakke i det typiske innlandsklima i Sør- og Midt Norge eller i de høyereliggende strøk i samme region.
Abstract
In the north-western European countries Norway, Sweden, United Kingdom (UK) and Ireland, variability in the forms, amounts and timing of phosphorus (P) loss from agricultural land is related to national differences in climate, soil, hydrological conditions and agricultural production. The dissolved form of P constitutes 9"93% of the total phosphorus (TP) in water, subsurface drainage can contribute 12"60% and surface erosion 40"88% of TP transfer. TP export in small agricultural streams is generally in the range 0.3"6 kg ha)1 year)1, with the highest losses in Norway and UK. All four countries are complying with the EU Water Framework Directive and developing a range of measures based on P source with transport controls over P losses. A decreasing trend in TP losses has been detected in agricultural streams following the introduction of measures to reduce erosion in Norway. Average P concentrations in Swedish streams have shown a reduction of nearly 2% per year since 1993 as a result of measures introduced in southern Sweden. However, in two large rivers in agricultural regions of Sweden, the concentrations of suspended solids (SS) and TP were shown to increase by 0.4% and 0.7% per year, respectively, over the period 1975"2004, possibly as a result of climate change. It is too early to detect trends in agricultural contributions to P in surface waters as a result of catchment-sensitive farming (CSF) in the UK and Ireland.
Authors
Ketil Haarstad Gro Hege LudvigsenAbstract
Pesticides in Norwegian ground water have been monitored since 1995. Here we report data including 2004. The monitoring has focused on shallow groundwater near agricultural fields (4 locations), farm wells (22 locations) and on public water works (38 locations), 450 samples were analyzed for a total of 62 pesticide compounds and metabolites, and the result was 514 detections of single compounds. Altogether 27 pesticides and metabolites were detected; 2 insecticides, 9 fungicides and 16 herbicides. Herbicides were most frequently detected (in 79% of the samples), followed by fungicides (20%) and insecticides (1%). Pesticide concentration was generally low, although high concentrations also occurred, for example 33 "g/l of metribuzine in shallow ground water near agricultural fields, and 20 "g/l of bentazon in a farm well. Some water soluble pesticides occurred both frequently and with relatively high concentrations in shallow ground water near agricultural fields. The results show that local ground water near farms is vulnerable for contamination of pesticides and needs further monitoring. Efforts should be made to minimize contamination of wells in farming areas through education on pesticide use, monitoring and well positioning. Few pesticides were detected in ground water from water works and the concentrations were low. Monitoring of water works ended in 2002. The data show that there is a continuous need to monitor pesticides as well as selected metabolites in shallow ground water and wells near agricultural fields in Norway.
Authors
Hugh RileyAbstract
Factorial combinations of N, P and K fertilizer have been compared with the use of farmyard manure at Møystad since 1922 in a seven-year crop rotation (3 ley, oat, potato, wheat, barley). Until 1982, low inputs of N fertilizer (22 kg ha-1) were used. In 1983, they were brought into line with current farming practice. This paper presents results of three subsequent rotations. Yields without any fertilizer were on average 48% of those with 100 kg N ha-1 in compound fertilizer, whilst those with 20, 40 and 60 Mg ha-1 farmyard manure were 81, 87 and 90%, respectively. Yields with other combinations of N, P and K declined in the order NP, NK, N, PK and K. When NPK fertilizer was used, apparent recoveries of applied fertilizer were close to 50% for N and K, and around 40% for P. Much lower values were found for nutrients applied singly. Balance between N supply and removal was indicated at rates of about 60 kg N fertilizer ha-1 in potatoes, 75 kg ha-1 in cereals and 90 kg ha-1 in leys. A surplus of P was found in all crops at all N levels, and of K in cereals and potatoes. In leys, K balance was achieved with an N supply of 90 kg N ha-1. Nutrient balance was indicated at a little below 20 Mg ha-1 yr-1 farmyard manure. Larger manure applications gave large nutrient surpluses, particularly of N. Soil reaction remained close to neutral with the use of calcium nitrate and manure, but declined with the use of ammonium nitrate. Manure use gave the highest amounts of available P, K and Mg in soil. Similar increases in total inorganic P were found with manure use as with fertilizer use, but amounts of organic P and total K were little affected.
Abstract
Several models for prediction of infection periods for lettuce downy mildew (Bremia lactucae) are based on the assumption that spores are produced at night and released in the early morning. The divergent light conditions at Nordic latitudes might affect both sporulation and spore release. Therefore, during the period 2001 to 2005 a total of 13 field trials were established in late season lettuce fields to evaluate efficacy of fungicide applications made according to the models PlantPlus (PP) and Modell-Analys (MA) in Norway. Disease severity varied from 0 to 89.4 % in unsprayed control plots at harvest. Fungicide treatments had a significant effect compared to untreated control in all but two of the field trials with disease incidence over 1 % at harvest. Fungicide applications at 10-day intervals and according to PP and MA resulted in an average of 3, 2.5 and 3.3 applications, respectively. There were no significant differences in disease severity at harvest between treatments according to 10-day interval, PP and MA for any of the field trials. Epidemics were created at two field locations that had no previous lettuce production, and a total of 59 days of spore trapping permitted the study of spore release under natural conditions. Spore production events predicted by MA were correct at 66 % of the days. However, when adjusting the criteria for spore production, 78 % of the days were correctly predicted.
Abstract
Virulence characteristics of Bremia lactucae populations from lettuce crops in the southeast and southwest of Norway from 2001 to 2005 were studied in relation to virulence factors (v-factors) and virulence phenotypes (v-phenotypes). The frequencies of 19 v-factors were analysed, and phenotypic diversity was calculated in relation to v-factors and v-phenotypes. A total of 39 different v-phenotypes were identified from the 58 samples analysed. Four of these were identical with the previously denominated races Bl:17, 18, 22 and 24. The most commonly occurring v-factors were v1, v2, v4, v5/8, v6, v7, v10, v11, v12, v13 and v18. V-factor v17 was not present in any of the tested isolates and v36 was found only once. V-factor v38 was first seen in 2004, coinciding with the observations of broken resistance in many cultivars. The population of B. lactucae in Norway was diverse, but not considerably different from other European populations of this pathogen.
Abstract
The prediction of infection periods for lettuce downy mildew (Bremia lactucae) is based on the assumption that spores are produced at night and released in the early morning. The divergent light conditions at Nordic latitudes might affect both sporulation and spore release. Therefore, we monitored release of B. lactucae spores in relation to the climatic conditions in lettuce fields to evaluate the performance of existing forecasting models in timing of fungicide applications for management of lettuce downy mildew in Norway. In 2005, epidemics were created at two field locations that had no previous lettuce production, and a total of 59 days of spore trapping permitted the study of spore release under natural conditions. Sporulation events were compared to predicted spore production events in Modell-Analys (MA). At the two locations, 76 % and 74 % of the spores were trapped between 08.00 and 16.00, respectively. Spore concentration icreased with decreasing relative humidity (RH), ofting coinciding with increasing solar radiation and temperature. Spore production events predicted by MA were correct at 66 % of the days. However, when the criteria for spore production were adjusted, 78 % of the days were correctly predicted.