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
Forfattere
Lars NesheimSammendrag
There is hardly any commercial growing of agricultural crops for energy purposes in Norway. Cereal straw is to some extent used as solid biofuel. The agricultural area constitutes only 3 % of the total land surface in Norway, and the area is so far used for grassland (65 %) and arable crops for food and feed (35 %). There is no reason to believe that production of energy crops will increase significantly in Norway in the near future, partly due to political reasons. In Denmark, Finland and Sweden cultivation of energy crops has been commercial for several years. The objective of this presentation is to give a review of the significance and types of possible energy crops in the Nordic countries, and particularly in Norway.
Forfattere
Venche TalgøSammendrag
Det er ikke registrert sammendrag
Forfattere
Knut Anders Hovstad Mikael OhlsonSammendrag
A field experiment was conducted in a semi-natural grassland to study the interspecific variation in the effect of litter on seedling emergence and establishment and separate physical from chemical effects. Seeds of seven forb species were sown in plots subjected to either litter amendment (0, 400 or 900 g m–2) or water extracts of litter (corresponding to 400 and 900 g litter m–2). In addition, an extract was treated with activated carbon to estimate the possible effects of secondary chemical compounds.The response to plant litter differed amongst species: negative, neutral and positive responses were observed. Anthriscus sylvestris was the only species with a strong positive response to litter. We found no consistent relation between seed size and response to plant litter. Physical effects of litter were generally stronger than chemical effects. However, water extract of litter inhibited emergence in three species. Activated carbon removed the negative effect of the litter extract, which suggests that the effect was caused by an inhibitory chemical compound rather than by increased competition in response to nutrients added via the extract. The balance between facilitative and inhibitory effects of litter depended on species identity and litter quantity. Facilitative effects dominated at low and intermediate quantities of litter, and inhibitory effects at high litter quantities. One species, Campanula rotundifolia, showed a switch from positive to negative responses with increasing quantities of litter. However, we found no general threshold for litter quantity valid across species.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Tor Håkon SivertsenSammendrag
Some ideas connected to the scope of scientific work in agronomy and agro meteorology and the scope of the scientific principle are outlined. Then the concepts of ‘sustainability" and ‘sustainable agriculture" are presented, and the content of different definitions of these concepts is discussed. Especially the idea of sustainability as conservation of important relations is discussed.Then the concept and principle of an allodial farm or free farm, connected to Norwegian law and Norwegian traditions is presented and the history of the present law is briefly outlined. Also traditions for passage of farms from one generation to the next generation in a few other European countries are mentioned. Then the concept of allodial farm is connected to the challenges of global change of Northern Europe, and the existing ideas of commercial agriculture.The following idea is discussed: "The idea of changing the focus in agricultural production from maximizing the crop yield to keeping the ecological system of the farming and the local area sound and in shape". Man is an organism like other organisms. He ought to take care of his surroundings and the other species, to take care of a totality of biological systems on the Earth. Probably no god or gods will take care of him if he does not succeed in doing this. The content of the concepts of adaptation and mitigation connected to global change is also finally mentioned.
Forfattere
Tor Håkon SivertsenSammendrag
An overview of an interpretation of the sicetific principle used in meteorology and agro meterorology is presented.And some implications of this interpretation connected to documentation of quatitative data and models is shortly discussed.
Forfattere
Tor Håkon SivertsenSammendrag
Climate change scenarios provide alternative plausible future climate for the planet, each being an example of what might happen under a particular set of assumptions. Scenarios are not specific predictions or forecasts. Scenarios provide starting points for examining questions about the uncertain future climate.Some of the main processes connected to exchange of energy of the atmosphere of the planet usually are connected to radiation of short wave and long wave electromagnetic radiation. The global albedo of the short wave radiation is one important parameter, and the processes connected of the greenhouse gases water vapour and carbon dioxide in the atmosphere are extremely important elements of future scenarios.The total amount of output of fossil carbon into the atmosphere is of importance as well as the natural cycle of the carbon. Also there exist several important positive feedback systems. The amount of water vapor in the atmosphere is connected to the temperature of the air, or to be more specific the saturation vapour pressure of the water in the air is increasingly dependent on the temperature of the air. Usually a warm atmosphere then will contain more water vapour than a cold atmosphere, and this will make the atmosphere even warmer because water vapour is the most important greenhouse gas connected to long wave radiation.The ice cover of the Arctic and Antarctic regions as well as the glaciers in the high mountainous areas on the Earth are important for keeping the albedo of the short wave radiation of globe high. When the glaciers and the ice cover are melting, the albedo is decreasing and the consequence seems to be even more melting of ice.The ultimate worst case scenario seems to be that the ice cover and the glaciers of the planet melt down and the oceans receive all this water. The present situation seems to be like this:The total energy of short wave radiation, received by the planet: 100 unitsPlanetary albedo: 30%Total energy connected to the water cycle. 21 unitsAmount of yearly precipitation totally: 1000mmAverage residence time of a water molecule in the atmosphere: 10 daysTotal volume of ice on the planet: 33 x 106 km3 (~ 60 m of sea level equivalent)Total amount of CO2 in the atmosphere: 385 ppmIn order to understand the content and the challenge of the different scenarios I would like to know the value of the following parameters (every 5th year) of the scenarios:AlbedoTotal energy connected to the water cycleAmount of yearly precipitation totallyAverage residence time of a water molecule in the atmosphereTotal mass of ice on the planetTotal amount of CO2 in the atmosphere
Forfattere
Tor Håkon SivertsenSammendrag
There exist several very complicated mechanistic crop growth models, like SUCROS, CERES etc. These models are constructed by modeling quantitatively physiological processes in relation to environment. Some of these models have been used for predictions and consequences of global change.The model CERES, a model for cereal crops, is delivered by IBSNAT, The International Benchmark Sites Network for Agrotechnical Transfer, University of Hawai, Honolulu. This model contains output parameters of yield, biomass, phenological phases, soil water content etc. The input data are parameters describing the soil physics, the varieties of the cereal crop, and the weather. In addition management of fertilization and management of pests and diseases may be consideredThe input weather data of interest for the present discussion are simulations, scenarios, of future climatic conditions in different countries and different regions in Europe. The type of crop production basically connected to the model CERES are technically advanced commercial production of cereals on the large agricultural scale. The outcome of any study containing this model in the present shape, will be the limits of this type of agricultural production connected to quantitative scenarios of the future climate in the different regions of Europe.How should one attach the concepts of sustainable agriculture and global change to crop growth modeling?How should crop growth modeling be connected to sustainable farming systems and the challenges of globalchange.Has anyone tried to use crop growth models in a context of production, storage, distribution, consumption, and the treatment of waste connected to crop production.Several ecological systems of nature contain recycling of minerals and waste products. Has anyone tried to combine crop growth models to such ecological systems?How should the temporal and spatial scope of mechanistic crop growth models be evaluated and discussed?
Forfattere
Tor Håkon Sivertsen Josef Eitzinger Sabina Thaler Simone Orlandini Pavol Nejedlik Valentin Kazandjiev Visnja Vucetic Dragutin Mihailovic Branislava Lalic Emmanuel Tsiros Nicolas R. Dalezios Andreja Susnik K. Christian Kersebaum Nicholas M. Holden Robin MatthewsSammendrag
During the past decades, in connection with the development of computers, many new software tools were developed to be used for agricultural research as well as for decision making. For example, crop and whole farm system modelling, pest and disease warning models/algorithms, models for irrigation scheduling or agroclimatic indices can help farmers significantly in decision-making for crop management options and related farm technologies. In research models can be used to simulate and analyse the complex connections in the soil-plant-atmosphere system for example in the important field of climate change impacts on agricultural production. All these modelled systems and their interactions include however many different kind of uncertainties and limitations, such as trends in technology and human activities, models representation of reality, lack of knowledge on system responses or lack of calibration data. Much research was done worldwide in the field of model development, model improvements or model comparisons. The aims of Working group 1 of COST734 was a review and assessment of agroclimatic indices and simulation models relevant for various European agricultural activities. The results of an europeanwide survey are presented in this study. It includes an overview of most used agrometeorological or agroclimatic indices and process oriented crop models for operational as well as scientific applications, an analysis of the limitations for applications and an overview of spatial applications in combination with GIS and remote sensing in Europe.
Forfattere
Jerry Cross Catherine Baroffio Alberto Grassi David Hall Barbara Labanowska Slobodan Milenkovic Thilda Nilsson Margarita Shternshis Christer Torneus Nina Trandem Gabor VetekSammendrag
The sex pheromone of the raspberry cane midge has been identified and synthesised by East Malling Research and Natural Resourced Institute and has proved to be highly attractive and useful for pest monitoring. EMR coordinated a collaborative ring test of standard raspberry cane midge sex pheromone traps in 2006. The aims were to investigate the seasonal temporal pattern of the midge flight in different raspberry production regions of Europe and the relationship between the magnitude of catches and the numbers of eggs and larvae which developed subsequently in artificial splits in the primocane of untreated raspberry plantations. The standard raspberry cane midge sex pheromone trap used for the ring test consisted of a white delta trap containing a 20 x 20 cm sticky base and a rubber septum lure impregnated with 10 μg of the raspberry cane midge sex pheromone racemate. Pairs of traps, separated by >20 m, were deployed in the centre of raspberry plantations at a height of 0.5 m in Italy, Hungary, Norway, Poland, Russia, Serbia, Sweden, Switzerland, and the UK. The traps proved effective and easy to use for monitoring the flight of adult male raspberry cane midge. There were very large variations (> 30 fold) between plantations in total numbers of midges caught over the season, indicating plantations which are at comparatively low and high risk from the pest. Three generations of adult flight were apparent in Norway, Russia and Sweden and four generations in the central European countries with possibly 5 generations in Italy, though later generations were often difficult to distinguish. In the northern countries, the 1st generation first and peak flight occurred on Julian days 150 and 165, respectively, whereas in Italy the 1st generation first and peak flight occurred approximately on Julian days 110 and 130 respectively. The 1st generation flights occurred much earlier in polytunnel protected crops than in open field crops. Data obtained on the occurrence of larvae were variable in quality but a linear relationship between the peak numbers of males captured in the pheromone traps per week for a given generation (M) and the peak numbers of eggs and larvae per cm in splits in the primocanes for that generation subsequently (L) was apparent (L = 0.025 M; R2=0.61). A nominal threshold of 30 midges per trap per week had been proposed but the linear relationship derived indicates that this threshold, which would result in ~ 0.75 eggs + larvae/cm, is too high. In reality, the degree of larval infestation that occurs and the resultant severity of crop damage will depend on the numbers of natural splits in the crop. The ring test is being continued in several countries in 2007.