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
Climate change and its possible consequences on eroson and nutrient loss from an agricultural catchment in south- eastern Norway is presented.
Sammendrag
This analysis showed that significant differences in hydrology between catchments exist. In addition are large differences in hydrological characters obtained depending on the time resolution of the input data, in which scale, topography and subsurface drainage intensity to a large degree are assumed to be responsible for these differences. It is believed that a thorough understanding of the hydrological flow processes is necessary in the implementation of cost effective river basin management plans and in the selection of adequate measures. This study showed that data collected at the small scale are important in the calibration/validation of models to be used in scenario analysis for implementation of best mangement practices.
Sammendrag
Climate change and its possible consequences on eroson and nutrient loss from an agricultural catchment in south- eastern Norway is presented.
Sammendrag
The results of an analysis of runoff in 17 catchments, located in Norway, Estonia and Latvia are presented. Different parameters, like the coefficient of variation, skewness and kurtosis were calculated in addition to a number of additional parameters describing the hydrology. The calculations were performed on both hourly - and average daily discharges. The obtained results suggest considering the hourly discharges in the interpretation of hydrological processes in agricultural dominated catchments and its possible effects on nutrient and soil loss. In the light of expected climate changes, the hydrological characterisation could provide information about the possible developments in the hydrology and its consequences for nutrient and soil loss processes.
Sammendrag
A characterisation of the hydrological behaviour of four small agricultural catchments in Estonia and Norway was carried out using a flashiness index (FI). FI reflects the frequency and rapidity of short term changes in runoff values. A comparison of FIs based on hourly and average daily discharge indicated large within-day variations over very short time intervals. Large differences were observed between the Norwegian and Estonian catchments, irrespective of whether average daily discharge or hourly discharge values were used. A comparison of the FI and the base flow index (BFI) showed that high FI values corresponded to low BFI values. Norwegian catchments with high FI or low BFI values showed high nutrient losses, whereas the contrary was observed for the Estonian catchments. Although the FI does not a priori give information about the flow processes within catchments, we believe that the FI, as well as the BFI, might be helpful in explaining differences in nutrient and soil losses between catchments.
Sammendrag
Rapporten gir en oversikt over jordas P-AL status i dyrka jord på kommunenivå og i de enkelte delnedbørfeltene i Akershus. Hurdal kommune og kommunene i Follo og region Vest har generelt høyere P-AL nivå i dyrka jord enn de øvrige kommunene. For Follo og region Vest er årsaken sannsynligvis høyere andel grønnsaks- og bærdyrking. I Hurdal kommune er en forholdsvis stor andel av bruk med husdyr årsak til et relativt høyt middel P-AL nivå. Ved sammenligning av P-AL tallene fra perioden 1988-95 med perioden 2000-06 ser det ut til at det har vært en nedgang i jordas P-AL nivå på Øvre Romerike. I de øvrige regionene ser det ikke ut til at det har vært noen endring av betydning.
Forfattere
Haithem Bahri Daniel Rasse Cornelia Rumpel Marie-France Dignac Gerard Bardoux Andre MariottiSammendrag
Recent in situ 13C studies suggest that lignin is not stabilised in soil in its polymerized form. However, the fate of its transformation products remains unknown. The objective of the present research was to provide the first comprehensive picture of the fate of lignin-derived C across its transformations processes: 1) C remaining as undecomposed lignin molecules, 2) C in newly formed humic substances, i.e. no longer identifiable as lignin-polymer C 3) C in microbial biomass, 4) C mineralised as CO2, and 5) dissolved organic C. To achieve this objective, we designed an incubation experiment with 13C-labelled lignin where both elementary and molecular techniques were applied. Lignin was isolated from 13C labelled maize plants (13C-MMEL) and incubated in an agricultural soil for 44 weeks. Carbon mineralisation and stable isotope composition of the released CO2 were monitored throughout the incubation. Microbial utilisation of 13C-MMEL was measured seven times during the experiment. The turnover rate of the lignin polymer was assessed by 13C analysis of CuO oxidation products of soil lignin molecules. After 44 incubation weeks, 6.0% of initial 13C-MMEL carbon was mineralized, 0.8% was contained in the microbial biomass, and 0.1% was contained in dissolved organic C form. The compound-specific 13C data suggest that the remaining 93% were overwhelmingly in the form of untransformed lignin polymer. However, limited transformation into other humic substances potentially occurred, but could not be quantified because the yield of the CuO oxidation method proved somewhat variable with incubation time. The initial bacterial growth yield efficiency for MMEL was 31% and rapidly decreased to plateau of 8%. A two-pool first-order kinetics model suggested that the vast majority (97%) of MMEL lignin had a turnover time of about 25 years, which is similar to field-estimated turnover times for soil-extractable lignin but much longer than estimated turnover times for fresh plant-residue lignin. We conclude that natural lignin structures isolated from plants are rather unreactive in soil, either due to the lack of easily available organic matter for co-metabolism or due to enhanced adsorption properties. The data also suggest that fairly undecomposed lignin structures are the main reservoir of lignin-derived C in soils.
Forfattere
Trond HaraldsenSammendrag
Med milde og snøfattige vintere utsettes grasflater i barnehager for tråkk av små føtter nærmest hele året. Bruksintensiteten på årsbasis blir skyhøyt over treningsbaner til fotball, mens det i liten grad har vært fokusert på å skaffe til veie jord som tåler slik belastning. I flere større byer i Norge er eksisterende jord i barnehagene forurenset, og det er behov for å bytte med ren jord. Det er derfor viktig både å stille krav om ren jord og jord som tåler bruksbelastningen i et aktivt lekemiljø for barn.
Forfattere
Torleif Bækken Thrond Haugen Markus Lindholm Karl Jan Aanes Eva Skarbøvik Atle Hauge Bjørn Otto DønnumSammendrag
På basis av eksisterende data samt befaringer er tilstanden av vassdraget samt mulighetene for tiltak innen følgende tre hovedtema vurdert: 1) Kantsoner; 2) Flomdemping; 3) Biotopforbedrende tiltak. Oppdraget er utført for Bærum kommune.
Forfattere
Ketil HaarstadSammendrag
Det er ikke registrert sammendrag