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
Sammendrag
Kløvereng i vekstskiftet øker meitemarkaktiviteten. Etter 10 år var det høyere antallog biomasse av meitemark (da. regnorm, sv. daggmask) i et økologisk kornsystem(sv. spannmålsodlingssystem) enn i to konvensjonelle. Det var ingen forskjelli meitemarkbiomasse mellom et konvensjonelt og økologisk engsystem (sv.vallodlingssystem),men det var flere meitemark i det konvensjonelle. Flest grå meitemark(Aporrectodea caliginosa) ble funnet, deretter rosa (A. rosea) og stor meitemark(Lumbricus terrestris).
Forfattere
Liv Guri Velle Samson ØpstadSammendrag
Etter 1950 har det skjedd store endringar i landbruket, og mange tradisjonelle og ekstensive driftsformer har fått mindre omfang eller gått ut av bruk. Når beitebruken i område med kystlynghei fell bort, opphøyrer også sviing og andre skjøtselstiltak. I Noreg har ein klart å ta vare på ein gammal husdyrrase, norrøn stuttrompa sau (Ovis aries), i dei ytre kyststroka. Sauen er nøysam og godt tilpassa heilårsbeiting. Han er korthala, lettbygd og høgføtt, og finst i fleire fargevariantar. Denne sauen dominerte sauehaldet i Noreg til siste halvdel på 1800-talet.
Forfattere
Liv OstremSammendrag
Auka nedbør og temperatur i snitt for heile året gir tidlegare vekststart om våren, seinare avslutning av veksten om hausten og dermed fleire vekstdøgn totalt i vekstsesongen. På sikt kan vekstsesongen auka med eit par veker om våren og det doble om hausten. Dette gir klimatiske vilkår bonden må forhalda seg til, og i lag med auka fokus på grovfôrkvalitet tilseier dette fleire slåttar og ei totalplanlegging av vekstsesongen frå våren av.
Forfattere
Frode Flemsæter Gunhild SettenSammendrag
In this paper we discuss relations between kinship, law, and property enactment. A recent revision of The Norwegian Act Relating to Concession in the Acquisition of Real Property is designed to influence the relation between subjects (property owners) and objects (properties) through ceasing the obligation of residency and cultivation on certain properties, which in turn is intended to increase sales prices of the respective properties. Drawing upon empirical research conducted in four Norwegian local authority districts, we argue that responsibility for past, present, and future generations of family or kin is highly important in property enactment. Although relations between subjects and objects are powerful and inform policy actions, relations between social subjects might be just as influential and powerful. When enacting properties, people may live in more complicated worlds than is often assumed. We assert that further research in legal geography and the emerging field of ‘geographies of relatedness’ might profit from seeing kinship and property as coconstituted.
Forfattere
Ketil Haarstad Pengxin Zhang Per Aagaard Farrokh Nadim Lars GottschalkSammendrag
The use of pesticides is a potential threat to local groundwater. Once groundwater is contaminated, it is very difficult to clean.Thus, it is of importance to assess the risk of contaminating local groundwater at an early stage when pesticides are found in soils. This knowledge will also help in remediation strategies. Traditional methods of deterministic analysis cannot explicitly account for the sometimes large uncertainties that exist at this stage in the work, whereas probabilistic analyses are better suited for dealing with these problems. In this paper, we have combined contaminant transport with a 1st-order reliability approach. Pesticide concentrations in soil have been studied to estimate the probability of failure—that is, of pesticides exceeding established critical levels in groundwater. Results indict that failure probability increases rapidly with in a certain range of pesticide concentrations in soil for different critical levels. In given aquifer conditions and contaminants, probabilities of contaminants exceeding particular critical levels can easily be obtained according to various water usage scenarios. The distribution of importance factors among variables indicates the contribution their relative weights make to the failure probability. Hence, authorities can easily form sensitivity factors to take action and reduce the risk of contaminating the groundwater.
Forfattere
Gunnhild Riise Trond Børresen Marit Almvik Randi Bolli Agnethe Christiansen Sven R. Odenmarck Cathrine Waage TveitSammendrag
Til tross for at lavdosemidler har blitt brukt som ugressmidler i korndyrkning i snart 30 år, har få feltstudier undersøkt avrenning av disse stoffene. Lavdosemidler benyttes i lave doser og brytes raskt ned. Risiko for avrenning til vannmiljøet har derfor antatt å være minimal. Dette studiet er det første kontrollerte feltstudiet av avrenning av lavdosemidler fra et kornområde i Norge.
Forfattere
Arve Heistad Razak Seidu Andreas Svarstad Flø Adam Paruch Jon Fredrik Hanssen Thor-Axel StenströmSammendrag
Tie long-term use of a filter-based, on-site wastewater treatment system increases nutrient discharge to receiving waters and may reduce its hygienic barrier efficiency. The main purpose of this research was to assess the hygienic barrier efficiency and the associated health risks of an on-site system that had exceeded its 5-yr design capacity with respect to phosphorus (P) removal. The system was investigated for bacteria and virus removal and assessed with respect to potential health risks in relation to reuse of effluent for irrigation. The system consists of a septic tank, a pressure-dosed vertical flow biofilter, and an up-flow filter unit with lightweight clay aggregates. The total P concentration in the effluent had increased gradually from initially <0.1 mg P L-1 during the first 2 yr of operation to 1.8 mg P L-1 after 5.3 yr. Escherichia coli was used as an indicator organism for fecal bacteria removal, whereas bacteriophages phi X174 and Salmonella typhimurium phage 28B (S.t. 28B) were used to model enteric virus removal. An overall decrease in E. coli removal occurred from a complete (approximately 5.6 log(10)) reduction during the first 3 yr of operation to 2.6 log(10) reduction. The removal amounts of the bacteriophages phi X174 and S.t. 28B were 3.9 and 3.7 log(10), respectively. Based on removal of S.t. 28B, the risks of rotavirus infection and disease for the investigated scenarios were above the acceptable level of 10(-4) and 10(-3), respectively, as defined by the World Health Organization.
Forfattere
Margarita Novoa Garrido T.M. Steinum C.L. Marolda M. A. Valvano H. SørumSammendrag
Organic acids are being used in animal husbandry due to their positive effects on overall health and growth rate in animal husbandry. However, little is known about the long-term effects of organic acids on the normal microbiota. In this work, an Escherichia coli strain isolated from a healthy pig was passed weekly for 20 months in medium with and without formic acid (FA) to investigate the effects of long-term exposure to organic acids. Passages were made using buffered medium at pH 5.25 and 6.1 with and without FA. Colonies showing reduced O antigen lipopolysaccharide production and increased susceptibility to FA were isolated after 12 months exposure to FA at pH 5.25 and after 20 months exposure to FA at pH 6.1. Adaptation to acid and bacterial growth was strongly affected by FA at pH 5.25. Also, after 2 months of serial passages, we observed colonies exhibiting multicellular behaviour, with production of fimbriae and an extracellular matrix. We conclude that long-term exposure to FA of an E. coli isolate from the normal intestinal microbiota is associated with various changes in the bacterial cell surface involving reduced O antigen expression and increased extracellular matrix production together with increased susceptibility to FA.
Sammendrag
One of the major concerns regarding use of velvet bentgrass in Scandinavia is whether current cultivars are sufficiently tolerant to frost. In 2008-09 the four velvet bentgrass (VB, Agrostis canina L.) cultivars Avalon, Greenwich, Legendary, and Villa, and the creeping bentgrass (CB, Agrostis stolonifera L.) cultivar Penn A-4 (control) were established from seed in 7.5x10x10 cm pots filled with a USGA-spec. sand containing 0.5% (w/w) organic matter. The following four treatments representing different phases of cold acclimation were compared: (i) nonacclimated (NA) plants maintained at 18 °C/12 °C (day/night) and 16 h photoperiod (150 μmol/m/s); (ii) plants acclimated at 2 °C and 16 h photoperiod (250 μmol/m/s) for 2 wk (A2); (iii) plants acclimated as ii plus 2 wk of sub-zero acclimation in darkness at -2 °C (A2+SZA2); and (iv) naturally acclimated plants under outdoor (field) conditions in November -December (FA). Freezing tolerance was assessed visually as percent of pot surface covered with healthy turf after 26 days of recovery in the greenhouse. To examine the relationship between physiological changes under cold acclimation and freezing tolerance, crowns of VB and CB were harvested for carbohydrate (CHO) analysis after each hardening treatment. Results showed that FA plants survived all freezing treatments (plant coverage more than 90 %). A2+SZA2 plants had better survival after freezing to -9 °C, -12 °C and -15 °C as compared with A2 plants. Differences in freezing tolerance between VB and CB were not significant. NA plants survived none of freezing temperatures. The predominant CHO in VB and CB crowns were sucrose and fructans. Compared with NA plants, A2 plants had significantly higher concentrations of fructose, sucrose and fructan. Exposure to -2 ºC in darkness (A2+SZA2) had no further effect on these concentrations. Natural hardening (FA) resulted in total carbohydrate and fructan concentrations significantly lower than for plants exposed to artificial acclimation.
Forfattere
Ricardo Holgado Stig Andersson Janet Rowe Ian Clark Christer MagnussonSammendrag
Cereal cyst nematodes (CCN), Heterodera spp. are well-known world-wide as parasites of cereals. In Scandinavia H. avenae is the most common species and occurs in the pathotypes, Ha11 and Ha12, and the additional pathotypes H. avenae-Knislinge, H. avenae-Ringsåsen and H. avenae-Våxtorp. H. filipjevi, which occurs in the two pathotypes, "East" and "West" is less common than H. avenae. For several years it has been known that resistance to cereal cyst nematodes may be found in some commercial cultivars, although no conscious breeding for resistance has been attempted. In 2004 and 2005 a majority of cereal cultivars on the Norwegian market were tested for susceptibility/resistance towards H. avenae pathotype Ha11, H. avenae pathotype "Våxtorp" and H. filipjevi pathotype "West" The test program included 30 cultivars of barley, 23 cultivars of oats and 6 cultivars of summer wheat. Resistance against Ha11 was found in 5 barley, 3 oat cultivars and in 1 wheat cultivar. Resistance against H. avenae pathotype "Våxtorp" was not present in barley, but 4 oat cultivars and 1 wheat cultivar were resistant. For H. filipjevi "West" resistance was not detected in wheat, but in 6 barley and 13 oat cultivars. Obviously the variability in CCN is larger than generally anticipated. In Norway management systems based on careful nematode identification and good knowledge of suitable resistant cultivars are in operation. Resistant barley is generally recommended when nematode populations are high due to its high tolerance compared to resistant oats. Farmers implementing this program have reported increased cereal yields of in average 1000 kg /ha. It has been calculated that by implementing this program in full the county of Vestfold could make an economic gain of 800 000 € annually. In perspective of increasing damage from CCN world-wide the recognition of its genetic variability is instrumental for successful control.