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
Hydrologiske karakteristikker fra mindre norske jordbruksdominerte nedbørsfelter ble presentert med særlig vektlegging av de ekstreme forhold. Fordeling av årsavrenning, antall dager det tar for å drenere 50 og 90 % av åravrenning, forskjellen mellom gjennomsnittlig døgnavrenning og maks døgn avrenning, flashiness komstante mm. Hva skal være konsekvensen for erosjon, næringsstofftap med klimaendringer.
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.
Forfattere
Johannes DeelstraSammendrag
En oversikt er gitt over hvilke modeller som er blitt bruk, med de viktigste resultater. Hvilke krav må bli stillt når modellene skal fungere innenfor norske nedbørsfelter. Modellenene må kunne takle norske vinterforhold med frysing/tining og frost utvikling i jord. Samtidig må den være istand til å kunne håndtere hydrologien i norske jordbruksdominerte nedbørfelter som er ofte domineret av grøftesystemer.
Sammendrag
This paper discusses the monitoring network for diffuse pollution from agriculture in Estonia in the context of implementation of the EU Water Framework Directive (WFD) and the Nitrate Directive (ND). Seven surface water monitoring stations in agricultural catchments represent two out of three river basin districts designated in Estonia according to the WFD criteria. The national monitoring programme of ground water quality involves 516 stations of which about half were monitored in 2005. The monitoring sites cover all main ground water bodies in Estonia but are largely concentrated in the Nitrate Vulnerable Zone (NVZ). Analyses did not reveal any significant trends in total nitrogen (TN) and total phosphorus (TP) concentrations in studied rivers during the last 15 years except in one site. The ground water quality stabilised after decrease of nitrate concentrations in the early 1990s, especially in the south part of the NVZ, but even in 2005 the nitrate concentration exceeded 50 mg l1 in 42 out of 145 ground water samples in this region. The existing surface water quality monitoring network provides only restricted information to select between different management options when implementing action programmes for the NVZ and the river basin management plans (RBMP) under the WFD.
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
1. Results for Cornell University, New York: The optimal pH for velvet bentgrass was around 5.0, but velvet bentgrass was not sufficiently wear tolerant at an annual input of only 0.75 kg N/100m2/yr 2. Report from Rutgers University, New Jersey: The recuperative potential of velvet bentgrass is considered poor, but our findings have shown that the wear tolerance of velvet bentgrass is just as high as for creeping bentgrass and that the high density of velvet bentgrass will restrict Poa annua encroachment under trafficked conditions 3. Bosch & Mitowski 2006 Master thesis, University of Rhode Island : - Greenwich provides better turf quality than Avalon - More than 2.0 kg N/100 m2/ yr necessary to produce acceptable quality of on USGA greens - Around 3.0 kg N/100 m2/ yr may be necessary to produce acceptable quality on straight sand greens in regions with 6-7 months growing period". However, lower N-rates may be acceptable with the use of iron, especially at high pH. - Topdressing and vertical mowing had little effect in this 2 yr study, but in general, velvet bentgrass greens seems to need vertically mowing and topdressing at least one a month to avoid soft and "puffy" greens Statement: "The common perception that velvet bentgrass is a low maintenance species may not always be true, at least not on sandy greens". 4. Irrigation research, Rutgers University, New Jersey: The water consumption increased in the order velvet bent
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
Karsten Raulund-Rasmussen Inge Stupak Nicholas Clarke Ingeborg Callesen Helja-Sisko Helmisaari Erik Karltun Iveta Varnagiryte-KabasinskieneSammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Rapporten vurderer ut fra eksisterende litteratur og ved hjelp av modell- og prognosekjøringer konsekvensen av ”hogstfredning” og ulike omløpstider i skog på karbonbinding. Resultatene antyder at høyest samlet karbonbinding i vegetasjon og jord vil oppnås ved lengre omløpstider (anslagsvis 30-50 år på middels bonitet) enn de såkalt ”normale” omløpstider i skogbruket. Det knytter seg først og fremst usikkerhet til trærnes vekst og avdøing ved utvidet omløpstid. Bledningshogst er vurdert til ikke å være et realistisk alternativ til ensalderskogbruket når det gjelder å øke karbonbinding i skog. Prognoser på landsbasis viser at den produktive skogen i Norge vil øke til en biomasse på ca. 2.1 milliarder tonn (i trær og jord) i løpet av 50 år, dersom den ble fredet fra hogst. Den årlige karbonbindingen ville da øke i en periode på 30 år for deretter gradvis å avta på grunn av skogens alderssammensetning. Med dagens hogstnivå i 50 år framover, vil biomassen i skog bygge seg opp til 1,5 milliarder tonn (i trær og jord). Høsting av GROT (greiner og topper) til energiformål vil bety lite for de totale karbonmengder i skog. Reduksjonen i CO2-utslipp ved utstrakt bruk av GROT (60-70% av potensialet) til energiformål vil ligge i størrelsesorden 1,5-2% av de totale norske utslippene i dag. Dersom man skulle bruke 3 millioner m3 tynningsvirke til bioenergiformål i tillegg til å nytte GROT, vil CO2 besparelsene totalt ligge på 3,5-4,5% av dagens norske utslipp.