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.
2008
Sammendrag
A major concern regarding use of velvet bentgrass (Agrostis canina L.) in Scandinavia is whether the current cultivars have sufficient winter hardiness. The objective of this study was to compare the tolerance of the four velvet bentgrass cultivars "Avalon", "Greenwich", "Legendary" and "Villa" to various types of winter stress with that of creeping bentgrass (Agrostis stolonifera L. ) "Penn A-4" under controlled conditions. To evaluate tolerance to freezing temperatures, unhardened and hardened plants were frozen at ar rate of 2°C per hour to -6, -9, -12 and -15°C. On average for two hardening conditions, all velvet bentgrass cultivars survived freezing marginally, but significantly better than `Penn A-4" (Table 1). Hardened plants had almost five times higher turf coverage than unhardened plants. Most plants survived freezing to -6°C, but hardly to -9°C, and not to -12°C and -15°C. A significant cultivar x hardening interaction indicated that `Greenwich" had higher freezing tolerance then the other cultivars only in the unhardened state To test tolerance to ice cover, snow cover and/or pink snow mould, unhardened and hardened plants were either unsprayed or sprayed with a mycelial suspension of Microdochium nivale and then incubated for 6 or 12 weeks in darkness at 0.5-1.0°C, either uncovered or enclosed in air-tight vacuum bags (simulating anaerobic conditions under ice cover), or covered with a sheet of wet cotton and wrapped in plastic (simulating snow cover). As a main effect, `Penn A-4" survived these winter conditions better than the velvet bentgrass cultivars. Among the velvet bentgrasses, winter survival of `Avalon" was inferior to that of `Villa", `Legendary" and `Greenwich". Better survival of `Penn A-4" was primarily due to better tolerance to M. nivale (Figure 2), not to ice or snow cover.
Forfattere
Britt I.F. Henriksen Egil PrestløkkenSammendrag
Økologisk husdyrproduksjon har som mål å være basert på 100 % økologisk fôr. Mangel på økologiske proteinvekstar til kraftfôrproduksjon i Europa, og eit forbod mot å bruke fiskemjøl til drøvtyggarar i EU har ført til auka behov for økologiske fôrvarer for produksjon av kraftfôr i Norsk økologisk husdyrproduksjon. Erter er den mest vanlege proteinveksten i økologisk produksjon i Noreg. For drøvtyggarar har erter lågt innhald av bypass-protein samanlikna med vanlege proteintilskot som rapsmjøl og soyamjøl. Det er derfor behov for andre høgverdige proteinvekstar med komplementære eigenskapar for å møte fôrkvalitetskrava til drøvtyggarar, gris og fjørfe. Oljevekstar som har høgt innhald av både feitt og protein vil bli av stor betyding dersom utfordringane i forhold til dyrking blir løyst. Vi har førebels få erfaringar med oljevekstar i økologisk landbruk. I eit fireårig prosjekt "Organic protein feed and edible oil from oilseed crops" vil ein utvide desse erfaringane og i tillegg vurdere fôrkvaliteten til økologisk dyrka proteinvekstar som raps, rybs og Camelina. Prosjektet vil skaffe kunnskap om nedbrytingsgraden av protein, stivelse og NDF (neutral detergent fibre) i vom og nedbrytingsgraden av protein og stivelse i tarm i økologisk dyrka proteinrike vekstar som er nødvendig for produksjon av kraftfôr med optimal fôrkvalitet.
Forfattere
Christian UhligSammendrag
This study reassessed the long-term effects (10 years) of different revegetation methods for the reclamation of a steep sandy slope under sub-arctic conditions. Four different organic based erosion control mats a) coconut, b) straw, c) coconut/ straw and d) wool in combination with the three propagated native plant species i) Poa pratensis (seeds), ii) Festuca rubra (seeds) and iii) Betula nana (transplants) and fertilizer treatments were studied. An assessment three years after establishment of the experiment indicated that the majority of the selected materials and methods gave satisfying results. However, reassessment after 10 years gave a rather opposite result. With exception of the wool mat none of the erosion control mats gave any long-term advantages. The coconut mat had not changed in physical appearance and represented a hinder rather than an advantage for plant establishment and soil development. In contrary few remains of the straw and straw/ coconut mats could be found and there were no obvious signs of any beneficial effect of these materials. None of the seeded native grass species were alive after ten years, but the majority of the Betula nana transplants had survived. Apart from increased survival and growth rates of B. nana, the most obvious effect of mineral fertilization was a higher appearance of Polytrichum sp. Consequently, results from this study clearly emphasizes the importance of repeatedly reassessment of revegetation efforts to avoid recommendations of short-time operational but long-time inappropriate revegetation materials ands methods.
Forfattere
Hugh RileySammendrag
Use of mineral NPK fertilizer and animal manure has been compared since 1922 in two trials on morainic loam soil at a former research station, Møystad, near Hamar, southeast Norway. Yield results for the period 1983-2003 were reported recently (Riley 2007). During this time cattle manure at rates of 20, 40 and 60 Mg ha-1 yr-1 gave 81%, 87% and 90%, respectively, of the yields obtained using 100 kg N ha-1 yr-1 and adequate P and K supply, in mineral fertilizer. Approximate balance between the supply and takeoff of N, P and K was achieved at the lowest manure rate, but higher manure rates resulted in large surpluses of all three nutrients. In order to study possible residual effects, no manure has been applied from 2004 to 2007, and mineral fertilizer has been withheld from one of the NPK treatments in each trial. The residual effects are evaluated in relation to both control plots that have not been fertilized since before 1922 and plots that have received 100 kg N, 25 kg P and 120 kg K ha-1 yr-1. Cropping in these four years was 2nd-4th year timothy/meadow fescue ley followed by oats. No residual effects of the mineral fertilizer treatments were found. Previous use of manure, on the other hand, has given large residual effects, with only a slight decline over the four years. These responses in relation to the use of mineral fertilizer and the residual supply of N, P and K from manure, estimated from its uptake in crops, will be presented at the seminar.
Forfattere
Goswin Heckrath Marianne Bechmann Petri Ekholm Barbro Ulen Faruk Djodjic Hans Estrup AndersenSammendrag
Compliance with the Water Framework Directive (WFD) will require substantial reductions in agricultural phosphorus (P) losses in the Nordic countries Denmark, Norway, Sweden and Finland. Falling P surpluses in agriculture for more than a decade and voluntary programmes of good agricultural practice have not reduced P losses to surface waters, while general regulatory measures have primarily focused on nitrogen. Without addressing the role of critical source areas for P loss, policy measures to abate diffuse P losses are likely to be ineffective. This has created a demand by environmental authorities for instruments that assess the risk of P losses from agricultural land and facilitate the planning of mitigation measures. In Nordic countries index-type risk assessment tools for diffuse P losses are under development inspired by experiences with P indexing in the USA. A common feature is that they are empirical, risk-based, user-friendly decision tools with low data requirements. Phosphorus indices vary between the four Nordic countries in response to different agriculture, soil and climate. These differences also result in different recent average annual agricultural P load estimates to the sea of 0.3, 0.5, 0.5 and 1.1 kg total P ha1 in Denmark, Norway, Sweden and Finland, respectively. In initial evaluations, Nordic P indices explained a large degree of variance in P losses at the field or catchment scale, but comparative data are still limited. To gain acceptance amongst stakeholders and inform river basin management planning in Nordic catchments as part of the WFD, it is crucial to more thoroughly evaluate the performance of these indices" at the field and catchment scale.
Sammendrag
Aerial dispersal of inoculum is critical to the spread of many plant diseases; including potato late blight (Phytophthora infestans (Pi)), lettuce downy mildew (Bremia lactucae (Bl)) and cucurbit downy mildew (Pseudoperonospora cubensis (Pc)). In addition to relative humidity and temperature, spore survival during aerial dispersal is affected by solar irradiation (SI), in particular during long-distance transport at higher altitudes. We evaluated the potential survival of spores in air by placing detached spores of Pi, Bl and Pc on filter paper in either direct sun or shade at time intervals from 0.5 to 3 h (Pi and Bl), or up to 42 hours (Pc). Thereafter, the filter papers were placed in moist chambers for 15 min prior to incubation on pea agar (Pi) or water agar (Bl and Pc) for 24 h, before the viable spores were enumerated. Spores were considered viable if they exhibited a germ tube or released zoospores. Preliminary results show that no spores of Pi, Bl and Pc germinated after 1, 3 and 30 h exposure to direct sun, with critical SI doses near 700, 2000 and 8500 Wm-2, respectively. In shade, no Pi spores germinated after 3 h, while spores of Bl and Pc were still viable after 3 and 42 h, respectively. In Norway, the potential for long distance distribution of Pi is restricted, but more likely for Bl and Pc. Further experiments will be conducted to find the maximum survival time for spores of these pathogens under Norwegian climatic conditions.
Forfattere
Rahel C. Brändli Thomas Hartnik Thomas Henriksen Gerard CornelissenSammendrag
Organic pollutants (e.g. polyaromatic hydrocarbons (PAH)) strongly sorb to carbonaceous sorbents such as black carbon and activated carbon (BC and AC, respectively). For a creosote-contaminated soil ("15PAH 5500 mg/kg dry weight) and an urban soil with moderate PAH content ("15PAH 38 mg/kg dw), total organic carbon"water distribution coefficients (KTOC) were up to a factor of 100 above values for amorphous (humic) organic carbon obtained by a frequently used Linear-Free-Energy Relationship. This increase could be explained by inclusion of BC (urban soil) or oil (creosote-contaminated soil) into the sorption model. AC is a manufactured sorbent for organic pollutants with similar strong sorption properties as the combustion by-product BC. AC has the potential to be used for in situ remediation of contaminated soils and sediments. The addition of small amounts of powdered AC (2%) to the moderately contaminated urban soil reduced the freely dissolved aqueous concentration of native PAH in soil/water suspensions up to 99%. For granulated AC amended to the urban soil, the reduction in freely dissolved concentrations was not as strong (median 64%), especially for the heavier PAH. This is probably due to blockage of the pore system of granulated AC resulting in AC deactivation by soil components. For powdered and granulated AC amended to the heavily contaminated creosote soil, median reductions were 63% and 4%, respectively, probably due to saturation of AC sorption sites by the high PAH concentrations and/or blockage of sorption sites and pores by oil.
Sammendrag
Increasing levels of Fusarium toxins, particularly deoxynivalenol (DON), T-2 /HT-2 and moniliformin, have been recorded in Norwegian cereals during the last few years. Previously F. avenaceum, F. culmorum, F. poae and F. tricinctum were the most common Fusarium species found on cereals in Norway. However, more recently F. graminearum has occurred more frequently, and the T-2/HT-2 toxin producing species F. langsethiae has also been detected, especially in oats. Investigations were made to clarify if there has been a change in the composition of Fusarium species. We are aiming to establish a three-step screening system in order to identify grain lots with high levels of Fusarium toxins: 1- Identify `high-risk" fields/lots, based on information on cultivation practice and climatic conditions, through the use of a FHB-prediction model. 2- Analyze the `high-risk" lots using a rapid test selected for its capacity to detect Fusarium toxins in a large number of grain samples at low cost. 3- Forward selected samples (based on analyses in step 2) for chemical mycotoxin analyses. Since 2004, we have run chemical mycotoxin analyses on grain samples from oat and spring wheat grown in Norway under different climatic conditions. Prediction models will be developed to estimate the risk of Fusarium infection and mycotoxin development in cereal fields, based on data for weather and cultivation practices. Preliminary results from using the prediction models will be presented.
Sammendrag
From 2002 to 2007, the number of organic farms in Norway has increased slightly, from 2303 to 2611. The area of organically certified and in conversion farmland has increased much more, from 32,499 to 49,563 ha. Hence, the average size of organic farms has increased considerably, from 19.7 to 25.5 ha agricultural area per farm. This is 20 % above the Norwegian average farm size. As parallel production is permitted, many farms have both organic and conventional production. The average organically managed agricultural area has increased from 11 to 15.4 ha per farm, and the number of milking cows on organic dairy farms from 15 to 20. Many small farms have opted out of certified organic agriculture, whereas farmers with more land are converting to organic. While most of the public financial support in Norwegian agriculture is differentiated in relation to farm size and region, support for organic agriculture is little differentiated. This encourages the conversion of larger operations. However, the diversity of the organic sector is reduced when smaller farms do not convert or opt out, and it should be considered how organic farming can be an interesting option for farmers independent of farm size.
Sammendrag
Aerial dispersal of inoculum is critical to the spread of many plant diseases; including potato late blight (Phytophthora infestans (Pi)), lettuce downy mildew (Bremia lactucae (Bl)) and cucurbit downy mildew (Pseudoperonospora cubensis (Pc)). In addition to relative humidity and temperature, spore survival during aerial dispersal is affected by solar irradiation (SI), in particular during long-distance transport at higher altitudes. We evaluated the potential survival of spores in air by placing detached spores of Pi, Bl and Pc on filter paper in either direct sun or shade at time intervals from 0.5 to 3 h (Pi and Bl), or up to 42 hours (Pc). Thereafter, the filter papers were placed in moist chambers for 15 min prior to incubation on pea agar (Pi) or water agar (Bl and Pc) for 24 h, before the viable spores were enumerated. Spores were considered viable if they exhibited a germ tube or released zoospores. Preliminary results show that no spores of Pi, Bl and Pc germinated after 1, 3 and 30 h exposure to direct sun, with critical SI doses near 700, 2000 and 8500 Wm-2, respectively. In shade, no Pi spores germinated after 3 h, while spores of Bl and Pc were still viable after 3 and 42 h, respectively. In Norway, the potential for long distance distribution of Pi is restricted, but more likely for Bl and Pc. Further experiments will be conducted to find the maximum survival time for spores of these pathogens under Norwegian climatic conditions.