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.
2003
Sammendrag
Utilstrekkeleg tilføring av kobolt, kopar og sink gjennom grovfôr til sau og lam frå innmarka kan sikrast ved bruk av mineralblanding om vinteren og i beiteperioden på innmark. Gjødsling med kobolt på eng er vanskeleg dersom pH er høg. Kobolt, kopar og sink vert mindre tilgjengeleg for plantene i jord med høg pH.
Sammendrag
Utilstrekkeleg tilføring av kobolt, kopar og sink gjennom grovfôr til sau og lam frå innmarka kan sikrast ved bruk av mineralblanding om vinteren og i beiteperioden på innmark. Gjødsling med kobolt på eng er vanskeleg dersom pH er høg. Kobolt, kopar og sink vert mindre tilgjengeleg for plantene i jord med høg pH.
Forfattere
Arild AndersenSammendrag
Artikkelen beskriver arter, utbredelse, utseende, biologi, vertplanter, skadeomfang, bekjempelse for forskjellige minerfluer som går på korn og gras. Artikkelen er en revidert utgave av Småskrift 9/89.
Forfattere
Trond Knapp Haraldsen Per Anker PedersenSammendrag
Det er ikke registrert sammendrag
Sammendrag
Stadig større mjøldoggproblemer i de siste årene har økt interessen for tolerante sorter. Høsten 2002 ble fem nye tolerante sorter sammenlignet med målesorten "Indira" i paraplykultur med bruk av kunstig lys. Resultatene viser at "Indira" fortsatt er et sikkert sortsvalg. Vektlegges holdbarhet, kan "Aviance" prøves.
Forfattere
Trygve S. AamlidSammendrag
Ved en feil er Moddus blitt uteglemt i tabellen for vekstregulering til frøeng i Felleskjøpets nye katalog "Plantekultur 2003/2004". Denne artikkelen oppsummerer de siste års forsøksresultater med vekstregulering av frøeng av timotei, engsvingel og rødsvingel.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Anne-Maj Gustavsson Helge Bonesmo Marketta RinneSammendrag
Under the Nordic climatic conditions, the growth of grass in primary growth is very intensive, but simultaneously the crude protein concentration and digestibility rapidly decline. Further, the rates of change vary considerably between years and sites due to varying environmental conditions. The most important environmental factors affecting the grass growth and development are solar radiation, temperature, day length, plant-available soil water, plant-available soil nitrogen and overwintering conditions. The managerial tactics available to producers for optimising the quantity and quality of forages are to vary the proportion between grasses and legumes, the amount of nitrogen fertiliser and the time of harvest. A reliable method to predict the changes in dry matter yield, chemical composition and digestibility would make it possible to optimise the time of harvest. Mathematical models can be very useful in simulating daily growth and changes in quality of grass. Examples of models of different complexity and advisory services based on them are described in the paper.
Sammendrag
Hydrological models are the foundation for prediction of erosion and losses of nutrients, pesticides and other pollutants to water resources. In South-east Norway the winter season is the most important hydrological period of the year, and it is characterised by sub-zero temperatures, soil frost and snow. It is therefore necessary that models can simulate these conditions properly. We tested the Coupled mass and heat balance model for soil-plant-atmosphere systems (CoupModel) on experimental data from winter 2000-01. Snow depths, soil temperatures, liquid and total water content were measured in a farm field in the Skuterud catchment, South-east Norway, where winters are unstable with several freeze-thaw episodes and snowmelt events. It was noticed that soil temperatures measured in the field deviated from measurements at other stations in Ås, so the model was also tested against a limited data set from the other stations. The model performed fairly well after adjusting parameters related to snow accumulation and snow depth. It was also shown that a daily input resolution may be insufficient for simulating snow dynamics in areas with large diurnal temperature fluctuations during the winter season. Soil temperatures at the experimental site were not satisfactorily reproduced, whilst the agreement between simulations and soil temperatures from the other stations was good. The model was validated on snow depths and catchment runoff for all winters between 1995 and 2002, and in most years the model performed equally well as in 2000-01. The main problem was that small snowfall events in autumn and spring were not simulated. The melt efficiency parameters had to be reduced when simulating the cold winter 1995-96, which had continuous snow cover until spring melt. Parameter settings apparently depend on the climatic conditions. Relative errors for simulated runoff were rather large, so application of the model on catchment scale will require further adjustments/other approaches. Evidence for snowmelt infiltration was found by analysing the experimental data, and modelling indicated that this process was important during all melt events in winter 2000-01.
Forfattere
B. Michalzik Edward Tipping Jan Mulder J.F. Gallardo Lancho Egbert Matzner C.L. Bryant Nicholas Clarke S. Lofts J.F. Vicente EstebanSammendrag
DyDOC describes soil carbon dynamics, with a focus on dissolved organic carbon (DOC). The model treats the soil as a three-horizon profile, and simulates metabolic carbon transformations, sorption reactions and water transport. Humic substances are partitioned into three fractions, one of which is immobile, while the other two (hydrophilic and hydrophobic) can pass into solution as DOC. DyDOC requires site-specific soil characteristics, and is driven by inputs of litter and water, and air and soil temperatures. The model operates on hourly and daily time steps, and can simulate carbon cycling over both long (hundreds-tothousands of years) and short (daily) time scales. An important feature of DyDOC is the tracking of 14C, from its entry in litter to its loss as D014C in drainage water, enabling information about C dynamics to be obtained from both long-term radioactive decay, and the characteristic 14C pulse caused by thermonuclear weapon testing during the 1960s ("bomb carbon"). Parameterisationis performed by assuming a current steady state. Values of a range of variables, including C pools, annual DOC fluxes, and 14C signals, are combined into objective functions for least-squares minimisation. DyDOC has been applied successfully to spruce forest sites at Birkenes (Norway) and Waldstein ( Germany), and most of the parameters have similar values at the two sites. The results indicate that the supply of DOC from the surface soil horizon to percolating water depends upon the continual metabolic production of easily leached humic material. In contrast, concentrations and fluxes of DOC in the deeper soil horizons are controlled by sorption processes, involving comparatively large pools of leachable organic matter. Times to reach steady stateare calculated to be several hundred years in the organic layer, and hundreds-to-thousands of years in the deeper mineral layers. It is estimated that DOC supplies 89 % of the mineral soil carbon at Birkenes, and 73 % at Waldstein. The model, parameterised with "steady state" data, simulates short-term variations in DOC concentrations and fluxes, and in DO 14C, which are in approximate agreement with observations