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.
2014
Forfattere
Reidun Pommeresche Anne-Kristin LøesSammendrag
The diversity and density of springtails (Collembola) were studied in an organically managed grass-clover ley at Tingvoll experimental farm in NW Norway during 2011–2012. In total after one sampling in 2011 and 3 samplings in 2012, 42 species were identified. Our results included a new species for the Norwegian fauna, Onychiurus edinensis (Bagnall, 1935) and one species very unusual to agricultural soils, Oligaphorura ursi (Fjellberg, 1984). The most abundant species was Parisotoma notabilis (Schäffer, 1896), followed by three species of Mesaphorura Börner, 1901, two species of Protaphorura Absolon, 1901 and Isotomurus graminis Fjellberg, 2007. A high number of P. notabilis has also been found in pastures in Iceland (Gudleifsson & Bjarnadottir 2008), in forest habitats in Norway (Hågvar 1982, Fjellberg et al. 2005) and in agricultural soil in Denmark (Axelsen & Kristensen 2000) and Sweden (Lagerlöf & Andrén 1991). The average density of springtails was 7 917 individuals m-2 in 2011. In 2012, the density was generally higher and varied between 16 182 and 41 515. We have proposed a grouping of the species into “epigeic” and “endogeic”, dependent on the presence or absence of eye organs and colour. Such classification is relatively easy and may give useful information in cases when identification to species is not possible.
Forfattere
Sebastian Piotr Mazur Arnfinn Nes Anne-Berit Wold Siv Fagertun Remberg Berit Karoline Martinsen Kjersti AabySammendrag
Effects of ripeness (nearly ripe, ripe, fully ripe) and cultivar (‘Blink’, ‘Polka’ and ‘Senga Sengana’) on colour and chemical composition of strawberry fruits and their suitability for jam production, evaluated as stability during storage at 4 and 20 °C for 3 and 6 months, were investigated. Quality traits of fruits and jams were significantly affected by both ripeness stage and cultivar. However, after 6 months of storage, particularly at 20 °C, the effects of fruit ripeness and cultivar were considerably reduced. During jam storage, anthocyanins, ascorbic acid, chroma and hue were least stable in jams made from the least ripe fruits. Quality traits in jams made from ‘Senga Sengana’ were best preserved during storage, while quality and chemical composition in jams made from ‘Blink’ changed the most. In conclusion, fully ripe fruits were best suited for jam processing. Storage at low temperature was preferable and ‘Senga Sengana’ was the most and ‘Blink’ the least suitable cultivar for processing.
Forfattere
grete h m jørgensen Lise Aanensen Cecilie Marie Mejdell Knut Egil BøeSammendrag
The aim of this experiment was to investigate the effects of different winter weather conditions on shelter seeking behaviour of horses and their preference for additional heat. A total of 17 horses from different breeds were habituated to an experimental paddock with a double-room shelter. In one of the rooms a 1500 W infrared heater provided radiation heat, the other room was not heated. The horses were turned out in their regular paddocks for two hours and then moved to the experimental paddock, where they could stay either in the heated room, in the non-heated room or outside in the 10x6 m paddock. Using instantaneous sampling at one-minute intervals for one hour, a present observer recorded horse’s behaviour and location. A weather station recorded data on wind (directions and speed), precipitation, temperature and sunshine. We registered the horses’ breed, exercise level, body weight, height and body condition, and samples of the horses’ coats were taken for length and quality registration. A Kruskal Wallis test was performed on the preliminary data. We observed great individual differences in the horses’ preferred location under different weather conditions. Horses increased their activity during low temperatures, combined with wind and/or rain (P
Sammendrag
Gjennom 2013 ble det brukt 95 tonn glykol (100 %) til flyavising ved Sandefjord lufthavn Torp. Dette var litt høyere enn for 2012 da det ble brukt 90 tonn, men vesentlig lavere enn i 2010 da det ble brukt 146 tonn. I toppåret 2006 ble det brukt hele 254 tonn glykol. For baneavisingsmiddel var forbruket på 36 tonn formiat. Dette var høyere enn for 2012 da det ble brukt 18 tonn. Til sammenligning ble det brukt 35 tonn formiat i 2011 og 56 tonn i 2010. Baneavisingsmidlene ble brukt i januar, februar, november og desember. I Rovebekken ble det påvist glykol i en av de 46 ukeblandprøvene fra St. R. Prøven viste en lav konsentrasjon på 0,3 mg PG/l. Kravet i utslippstillatelsen er dermed overholdt. I 26 døgnblandprøver fra Rovebekken (St. R) prioritert for analyse av baneavisingsmidlet formiat, ble det påvist formiat i 8 prøver. Høyeste konsentrasjon på 283 mg formiat per liter ble påvist i en prøve fra 29.01.13. Prøven ble tatt etter utlegging av nærmere 9 tonn formiat knyttet til underkjølt regn 27. og 28.01.13. Tilsvarende ble det påvist 136 mg formiat per liter i en prøve tatt ut 29.02.13, etter utlegging av nærmere 6 tonn formiat i perioden 17. – 19.02.13. Automatisert overvåking av ledningsevne i Rovebekken (St. R) og i overvann fra banesystemet (St. G2) har gitt god oversikt over mønster og varighet av avrenning med baneavisingsmidler. ¨ Overvåking av oksygenkonsentrasjonen i Rovebekken har vist gode og tilfredsstillende forhold gjennom 2013. Det har vært periodiske problemer med målingene. I slike perioder har oksygenkonsentrasjonen i bekken blitt kontrollert med manuelt måleutstyr. For stasjonene med avrenning til Vårnes- og Unnebergbekken (St. N og S) ble det tatt ut 9 stikkprøver i løpet av 2013. I Vårnesbekken ble glykol påvist i tre prøver og formiat i fem. I Unnebergbekken ble glykol påvist i fire prøver og formiat i to. Høyeste påviste konsentrasjoner var 35 mg PG/l og 100 mg Fo/l. Samlet sett har 2013 vært et år med lite avrenning av glykol til Rovebekken, og utslippskravet er overholdt. Formiat har blitt påvist i bekkevannet etter større utlegg av baneavisingsmidler. Fiskeundersøkelsen viste lavere tetthet av ørret enn i 2012, med fravær av årsyngel. Manglende forekomst av årsyngel antas å ha sammenheng med bunnfrysing av bekken i løpet av vinteren.
Forfattere
Jorunn BørveSammendrag
Sweet cherry fruit in Norway are graded and packed with chlorinated water according to drinking water standards (max. 2 ppm free chlorine after fruit contact) as a transport medium in parts of the grading lines. A possibility of fruit contamination from fungal pathogens exists in such water. ‘Lapins’ fruit from 10 commercial orchards at each of three packinghouses were put through a simulated sale period (10 days at 2°C and 2-3 days at 20°C) either directly or after being transported on a grading line in 2007. In 2008, fruit were sampled at different times of the day (early, mid and late) and compared with the control. Fruit samples containing 5 x 100 fruits were weighed at time of sampling, after 10 days at 2°C (in a Lifespan bag) and after 2-3 days at 20°C. The number of fruit decayed with fungal pathogens were counted and diagnosed. Total fruit decay in a mean of 3 packing houses x 10 orchards was 14% before packing and 28% after packing in 2007. Brown rot (caused by Monilinia laxa) incidence decreased from 1.1% to 0.3% and Mucor rot (caused primarily by Mucor piriformis) incidence increased from 11% to 26%. In 2008, there were no significant differences between unpacked and packed fruits, or between the different packing hours, on the different fungal diseases or incidence of total fruit decay. These preliminary results indicate that there might be a risk of contamination in seasons with high levels of fruit decay (such as 2007), but in normal seasons a slight chlorination of water is satisfactory to minimize the risk to an acceptable level.
Forfattere
Ragnhild Nærstad SS. Sharma Vinh Hong Le Abdelhameed Elameen Arne Hermansen May Bente BrurbergSammendrag
Initial sources of inoculum of Phytophthora infestans were investigated in ten potato fields with early outbreaks of potato late blight. Infected plant samples and isolates from these fields were examined with respect to mating type prevalence, fungicide resistance and genotypes based on microsatellites A high proportion (91 %) of the isolates recovered were of mating type A1. However, both mating types were found in 3 of 9 fields with more than one isolate recovered, and sometimes both mating types were found on the same plant. Most of the isolates recovered from fields treated with metalaxyl-M prior to sampling had reduced sensitivity or were resistant to metalaxyl-M, and most of the isolates recovered form fields without metalaxyl treatment were sensitive. The isolates recovered from fields treated with propamocarb prior to sampling had a higher frequency of reduced sensitivity to propamocarb than isolates from fields without propamocarb treatment. We found that most plants contained more than one P. infestans SSR-genotype. Clustering analysis of the infected samples revealed that most samples clustered together according to fields. By combining information from P. infestans isolates and DNA extracts from the leaf lesions we found examples of both mating type A1 and A2 having the same multilocus genotype. This result indicates that both of these genotypes have a common ancestor, hence the inoculum originates from oospores. Although this a minor study of only 10 fields with a limited amount of isolates and plant samples, the results indicate oospores in the soil is an inoculum source. Hence the forecasting model to predict outbreaks of potato late blight should be modified to include this.
Forfattere
Cecilie Marie Mejdell grete h m jørgensen Linda J. Keeling Janne Winther Christensen Knut Egil BøeSammendrag
Group housing of horses is not very widespread, despite obvious advantages for their development and mental well-being. One often expressed rationale for this is that horse owners are worried about the risk of injuries due to kicks, bites or being chased into obstacles. To address this concern, we developed and validated a scoring system for external injuries in horses to be able to record the severity of a lesion in a standardized and simple way under field conditions. The scoring system has five categories from insignificant loss of hair to severe, life threatening injuries. It was used to categorize 1124 injuries in 478 horses. Most of these horses were allocated to groups to study the effect of group composition (i.e. same age or mixed, same gender or mixed, socially stable or unstable groups) on behaviour and injuries. The material included mainly riding and leisure purpose horses of different breeds, age and gender. Most injuries occurred the day after mixing. Injuries of the more severe categories 4 and 5, which normally would necessitate veterinary care and/or loss of function for some time, were not observed at all. The vast majority of the recorded injuries were category 1 lesions (hair loss only). A few such injuries were found on most horses, some horses had none, and a few had many. The second most common injury type was category two (abration/scrape into, but not through the skin, and/or a moderate bruise/contusion). Category 3 injuries (a minor laceration and/or contusion with obvious swelling) were only recorded in a baseline subset of 100 riding horses, there comprising 4% of the injuries. Whereas most of the injuries were found on the body, the category 3 injuries were mainly found on the limbs and head. The reason for this is probably that the skin there is tight and thus is more easily lacerated. Icelandic horses tended to have fewer and less severe injuries compared to other breeds. There was also a breed effect on location of the injuries. We conclude that the risk for serious injuries when horses are kept in groups is generally low and fear of injuries should not be a reason to prevent horses from social interaction with other horses. However, we emphasize that most of the recordings were performed during the summer period, and many horses were unshod. The situation might have been different in winter, and special caution should be taken if mixing horses shod with ice studs.
Sammendrag
Mange hesteeiere bruker dekken på sine hester under ulike forhold, både når de er ute, når de står inne, når de ris og under transport, men det finnes ingen oversikt over hvor stort omfanget av dekkenbruk er og hvilke oppfatninger hesteeierne har om bruk av dekken. Innlegg på nettsider, i blogger og i ulike hestetidsskrifter tyder på at hesteeiere har veldig klare, men likevel svært forskjellige oppfatninger om dekkenbruk. Hensikten med denne spørreundersøkelsen var å kartlegge bruk av dekken til hest i Norgeunder ulike vær- og oppstallingsforhold og for ulike hesteraser. Våren 2014 ble det utarbeidet en spørreundersøkelse med til sammen 41 spørsmål til hesteeiere og andre med ansvar for stell av hest om bruk av dekken. Spørsmål og aktuelle svaralternativer ble lagt inn i programmet Quest-back. Spørreundersøkelsen ble publisert på nettstedet til Norsk hestesenter, Norsk Rytterforbund, Norsk Travselskap og nettsiden www.hest.no, samt på nettsidene til NMBU, Veterinærinstituttet (VI) og Bioforsk og også spredt via Facebook. Undersøkelsen ble besvart av totalt 2075 personer som drev med hest. Majoriteten av hesteeierne (55,1 %) var i aldersgruppen 20 – 39 år og 95,6 % av hesteeierne var kvinner. Varmblods ridehest utgjorde den største gruppen (25,1 %) og deretter kom kaldblods ridehest (19,1 %) og Islandshest (14,6 %), men både varmblods og kaldblods travere, engelsk fullblods, arabisk fullblods, frieser og ulike ponnier var representert i materialet. 53,6 % av de 2075 hesteeierne oppga at hestene ble holdt i en isolert stall (med/uten varme) om vinteren, mens 16,5 % oppga at hestene var i en uisolert stall og 25,3 % at hestene gikk i et løsdriftssystem med tilgang til leskur. 83,7 % av de 2075 hesteeierne oppga at de brukte dekken på hestene under gitte forhold når de var ute, mens 16,3 % oppga at de aldri brukte dekken. De viktigste årsakene til at hesteeierne brukte dekken var lave temperaturer, nedbør og vind samt når hesten var svett etter bruk. Det var spesielt ved utetemperaturer under + 10 °C at det ble benyttet dekken på hester som gikk ute. 35,2 % oppga at hesten ble klippet. Nesten 95 % av hesteeierne som hadde varmblods ponnier eller varmblods ride- og kjørehester, oppga at de brukte dekken når hesten var ute. Bare 65,8 % av hesteeiere med kaldblods ponnier oppga at de brukte dekken når hesten var ute, mens tilsvarende tall for hesteeiere med kaldblods ride- og kjørehester var 78,8 %. 59,1 % av eierne bruker dekken på hesten når den står inne. For hester som var oppstallet i isolert stall om vinteren, svarte 92,5 % av hesteeierne at de benyttet dekken på hesten når den var ute, mens tilsvarende tall for hester oppstallet i uisolert stall eller uteboks var 86,9 % og 64,0 % i løsdriftssystemer med utegang. Blant de hesteeierne som klippet hesten sin var det 97,8 % som brukte dekken under noen forhold når hesten var ute, mens tilsvarende tall for de hesteeierne som ikke klippet hesten var 76,0 %.
Forfattere
Till SeehusenSammendrag
Abstract The object of the first study was to evaluate effects of long-term tillage regimes (ploughing- P and minimum tillage- M) on the bearing capacity of a clay loam soil and to determine the effects of wheeling with different wheel loads (4.1 Mg; 6.6 Mg) and wheeling frequencies (1x, 10x) of two slurry tankers on the soil’s functional parameters and crop yields. Paper I includes laboratory measurements of the precompression stress (Pc) to determine soil strength at -6 kPa in top- (20 cm) and subsoil (40 and 60 cm). Further, a combined stress-state and displacement transducer system was used to determine major principal stress (σ1) and vertical and horizontal soil deformation in the field. It was the first time this technique has been used under the climatic and farming conditions in Norway. The results show that the M plot had in the topsoil 74% higher Pc than the P plot, whilst the differences were less distinct in the subsoil. Wheeling increased Pc at all soil depths. Compared to ploughing, higher Pc in the upper layer of the M plot led on average to 60% (light tanker) and 48% (heavy tanker) reductions in the σ1 values. The extent of σ1 was dependent on the ground pressure in the topsoil. The first pass of a wheel caused the greatest damage in some cases, but all wheelings led to accumulative plastic deformation in both vertical and horizontal directions. The results show that soil water content is an important factor influencing bearing capacity. Wheeling with high intensity would have exceeded Pc in all cases in moist soil (matric potential -6 kPa). Drier soil (-100 kPa), in combination with minimum tillage, limited the occurrence of stresses exceeding Pc in the upper soil layer. The effects of tillage, wheel load and wheeling intensity on the hydraulic properties of this soil are described in Paper II. Soil physical analyses and a compaction verification tool (CVT) were used in order to assess the extent of damage to soil structure. In addition, grain yields are presented for the ten years before and two years after the compaction study. The yields in the period before compaction were strongly affected by tillage, ploughing giving on average 24% higher yield than direct drilling. Yields after compaction were affected by both previous tillage and compaction intensity. In the first year, single wheeling on the P plot gave 23% and 28% yield reductions with 4.1 Mg and 6.6 Mg wheel loads, respectively, whilst multiple wheeling gave 14 % reduction at 6.6 Mg wheel load. Yield reductions on the M plot ranged from 63% (1x wheeling with 4.1 Mg) to 100% (10x wheeling with 6.6 Mg). Similar trends were found in the second year. Soil physical data indicated that all wheeling led to changes in both top- and subsoil on both tillage plots. However, effects in the subsoil were partly masked by the soil’s high initial bulk density. The CVT suggested harmful compaction on both plots, with the M plot being less affected than the P plot. However, yield results did not support this conclusion, suggesting that other factors limited yields on the M plot. The second study was part of a multidisciplinary project addressing Fusarium aspects related to crop management, plant breeding and animal productivity. The main object of Paper III was to compare effects of ploughing versus reduced tillage and straw removal versus retention, on the amounts of plant residue, weed populations, soil structural parameters and cereal yields in four 3-year tillage trials (spring oats and spring wheat) on soils (clay loam, loam and silt) representative of cereal-growing in Norway. The methods included measuring straw residue cover, analyses of soil physical parameters, weediness, as well as crop yields and quality. The results showed that the more intensive the tillage, the higher the amount of small and the lower the amount of large soil aggregates. Reduced soil tillage, and in some cases spring ploughing, gave significantly higher aggregate stability than autumn ploughing, thus providing good protection against erosion. However, decreasing soil tillage intensity generally increased the amounts of surface residues and weeds. Crop rotation with oilseeds also led to a higher amount of weeds, both in the oilseed itself and in cereals the following year. Straw treatment affected yields to only a small degree, whilst the effects of soil tillage varied between both year and soil type. There were only small yield differences between tillage systems on loam soil, whilst reduced soil tillage was superior on clay soil and inferior on silt soil. Our results suggest that shallow spring ploughing is a good alternative to autumn ploughing, as it gave comparable yields and better protection against erosion, and was nearly as effective against weeds. In Paper IV the influence of the various tillage regimes on the inoculum potential and dispersal of Fusarium spp. was evaluated. In order to assess the amount of Fusarium spp. on straw residues, samples from the previous year were collected after sowing. Inoculum potential was calculated as the percentage of the residues infested with Fusarium spp. multiplied by the proportion of the soil surface covered with residues. For the assessment of Fusarium inoculum transported over long distances, air samples were collected in spore traps. This is the first report in Norway of Fusarium species DNA collected in air samples above cereal fields. The results confirm that residues are an important source of inoculum and the inoculum potential of Fusarium spp. was significantly lower in ploughed plots compared to those with harrowing only. No differences in the inoculum potential were found between ploughing in spring and autumn, whereas harrowing in autumn generally reduced it more than did spring harrowing. Fusarium DNA was mainly detected in the samples collected from heading onwards, and the dispersal increased after rainy periods.
2013
Forfattere
Anita LandSammendrag
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