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
Sammendrag
Ein studerte om bladgjødsling med kalsium påverka fruktkvaliteten hjå plommer og kor haldbare fruktene var etter hausting. Bladgjødsling med kalsium hadde ingen signifikante verknader på fruktkvaliteten. Men kalsiumtilførsel syntest å utsetja mogninga noko (4 av 5 målte faktorar). Kalsiumhandsaming reduserte rotning under lagring av plommer. Men det var ingen sikre skilnader mellom dei ulike strategiane som var nytta. I eitt forsøksår var bladgjødsling tidleg i sesongen betre enn handsaming seint med omsyn til rotning etter hausting. I alle forsøka var det ein tendens til at frukter sprøyta med soppmiddel var mindre utsette for rotning enn kalsiumsprøyta frukter. Men skilnaden var berre signifikant i eitt forsøk.
Forfattere
Kristine Marie Olsen Unni Synnøve Lea Rune Slimestad Michel Verheul Cathrine LilloSammendrag
Det er ikke registrert sammendrag
Forfattere
Tor Håkon Sivertsen Janis GailisSammendrag
The history of a web-based system for administrating data from a network of agrometeorological stations is shortly presented, and the module of this system containing the documentation of the instruments in this network is discussed in detail. The quality concept of meteorological data is the starting point in this discussion. The way of coupling the instruments and parameters on each meteorological station is shown, as well as use of this information by controlling and correcting meteorological data. Ideas of actor-network theory are discussed connected to future challenges of data integration and use of data from different sources in applications.
Forfattere
Tor Håkon SivertsenSammendrag
The topography of the earth influences the movements of parcels of air in the atmosphere. Wind systems blowing across mountain ridges sometimes excite stationary gravity wave systems behind and above ridges witrh a breath of about 10 km. The conceptual discussion in this paper is connected to the transport of wave energy in stationary gravity waves and stationary gravity inertia waves , where there are discontinuities in the parameters describing the vertical stratified atmosphere. The discussion is closely connected to two theorems by Eliassen and Palm (1961) showing that the vertical flux of wave energy is conserved throughout the atmosphere for a great class of systems. But the boundary conditions used by Eliassen and Palm (1961) in the gravity wave systems connecting the vertical layers in situations with discontinuities do not cover all possible physical situations of interest.
Forfattere
Tor Håkon SivertsenSammendrag
The concept of "advection" is a concept connected to horizontal transport of energy and mass by parcels of air in convective flow systems. It is a concept mainly used in the field of `meteorology", and the concept is given a definition in `International meteorological vocabulary" published by WMO -No.182 " in 1992. Thiis concept is also used in other fields of science, especially by biologists studying evaporation of water in fields and forests , leaf wetness duration in orchards, frost situations in crop canopies etc. Because `environmental fluid mechanics" should contain contributions from several different fields of science, meteorology, agronomy, fluid dynamics, soil sciences, hydrology agro meteorology etc., it is of importance that the specialists from the different branches of scientific research of environmental phenomena understand each other. The main intention of this presentation Is making this concept of `advection"more clear for different groups of scientists, and this is also a way of advertizing the need for general conceptual discussions in the field of `environmental fluid mechanics". The definition of `advection" given by `WMO" is presented, and then the concepts of divergence and convergence of flow systems of air are presented. The concept of turbulent flow systems are then briefly connected to this concept; and the concepts of `oasis effect" and `clothline effect" are discussed. Equations containing energy balance in the close vicinity of the ground is presented, and the advective components in these equations are discussed. Then the physical cntent of the Penman-equation and the Penman-Monteith-equation of potential and actual evaporation is shortly presented and discussed.( Advection is not contained in these equations.) The content of an empirical statistical formula, derived by determining `potential evaporation" using measurements from pan evaporimeters, is presented and discussed. In this case an `advection term" appears, and this `advection term" is connected to the `oasis-effect" of the evaporometer, and elements of the advective weather situation are contained in the monthly variation of the statistical coefficients. The difference in scope when describing weather by `empirical statistical equtions" or by equations derived by fluid dynamical concepts is also discussed- The possibilities of including advection terms in operational use in weather systems of agro meteorology of local spatial and temporal scale is discussed. Finally ideas for modifying the definition given by WMO on `advective flow systems" is presented. References: Johannson, W., 1969, Meteorologiska elements inflytande på avdunstningen från Anderssons evaporimeter, Grunförbätring, 22, 82-105 ( in Swedish).(`The influence of the meteorological elements on the evaporation from Anderssons evaporimeter") Rosenbewrg, N.J., Blad, B.D., and Verma, S.B., 1983, Microclimate The Biological Environment, John Wile & Sons, New york, Chichester, Brisbane, Toronto, Singapore, 405 pp. International Meteorological Vocabulary,1992, WMO/ CMM/ BMO - No. 182 Thom, A.S., 1975, Momentum, Mass and Heat Exchange of Plant Communities, in `Vegetation and the Atmosphere" edeited by J. L. Montei9th, Academic Press, 278 pp
Forfattere
Tor Håkon SivertsenSammendrag
A few ideas connected to the scope of scientific work in agronomy and agro meteorology and the scope of the scientific principle is first outlined. Then the concepts of `sustainability" and `sustainable agriculture" is presented, and the content of different definitions of these concepts is discussed. General ideas of using quantitative parameters, indices, to measure sustainability is presented. Then different ways of defining indices is discussed.A concept connected to `subsistence farmimg" called `tiny orchard" is presented and discussed, and the possible use of this concept `tiny orchard" as a referenc system for measuring and definig `sustainable agriculture" is discussed. The actual life cycle of a commercial agricultural product , an apple to be consumed fresh, is outlined; and this is compared to what is happening in a `tiny orchard" with and apple on an apple tree. Some importantant cycles connected to sustainable agriculture is mentioned, the fresh water cycle and the cycles of nitrogen and phosphorous. The following idea is discussed:"The idea of changing the focus in agricultural production from maximizing the crop yield to keeping the ecolological system of the farming and the local area sound and in order". Man is an organism like other organisms. He ought to take care of his surroundings and the other species, to take care of a ttallity of biological systems on the Eatth. probaly no god or gods will take care of him if does not succed in doeng this.The content of the concepts of adaption and mitigation connected to clobal change is also finally mentioned. References and biblography: Leane, M., 2005, The quest for an Environmental Metric: gazing at weather systems, a ground-breaking scientist spawned on ecological accounting standard the Wall Street might one day embrace ( http:// www.cfo/printable/article.cfn/530007?f=options), CFO Publishing Maine, T., 2005, Towards a Metric of Sustanability ( http://www.isoconference.org.au/ papers/ Maine.pdf), CSIRO Publish Jain, R., 2005, Sustainability metrics, specific indicators and preference index (http://www.springerlink.com/media/h4d4779uuq0yynfhktb6/contributions/t/2/2/5/t22524055312t88.pdf), Clean Techn. Environ. Polocy /:71-72
Sammendrag
A main scourge in Norwegian sheep farming is tick-borne fever (TBF) caused by the bacteria A. phagocytophilum and transmitted by the tick Ixodes ricinus. The aim of this poster is to present a new research project on resistance to TBF in sheep (2007?2010).
Forfattere
Nicholas Clarke Yijie Wu Line Tau StrandSammendrag
Boreal forests are increasing in age partly due to reduced logging and efficient wildfire control. As a result, they also stock more carbon. Whether increased forest C stock causes greater production of dissolved organic carbon (DOC) is uncertain. DOC in bulk precipitation, throughfall and soil water was studied in 10-, 30-, 60- and 120-year-old stands of Norway spruce (Picea abies (L.) Karst.) DOC concentrations in throughfall and O horizon soil water followed the order 10<30<60 = 120 and 10 = 30<120<60, respectively. DOC fluxes followed the order 10 = 30<60 = 120 in throughfall, while no significant difference between stands was found for O horizon soil water. Above-ground tree litter varied according to 10<30<60 = 120, a pattern identical to that for DOC concentrations in throughfall and resembling but not identical to that for DOC concentrations in O horizon soil water. This indicates additional sources for DOC in soil water. Seasonality in DOC concentrations was observed at the base of the O horizon, and seasonality in DOC fluxes in both throughfall and O horizon soil water. Our results suggest differences in the polarity of DOC between the 10-year stand and the others, which we interpret as reflecting the lack of grown trees and possibly the different vegetation on the 10-year stand.
Forfattere
Anne Falk Øgaard Tore KrogstadSammendrag
Det er ikke registrert sammendrag
Forfattere
Anne Falk Øgaard Tore KrogstadSammendrag
In most of the profiles on clay soil there were high values of P-AL in the deepest layers. This was true also for the uncultivated soil, where the P-AL values were as high as 100-120 mg P kg -1. In the deepest layers of cultivated soil, P-AL values of 150-200 mg P kg-1 were observed in some of the profiles. These high values are probably a result of transport of P rich particles from the topsoil through macropores. This is supported by a significant positive relationship between P-AL in topsoil (0-10 cm) and the average P-AL at 80-100 cm depth, and a higher P-AL to Ca-AL ratio in the cultivated than in the uncultivated soils in deep profile layers. The P-CaCl2 concentration in the subsoil was zero or close to zero in all the profiles, despite high P-AL values. Increasing pH with depth influences the distribution of P among the different P fractions.