Nils Vagstad

Spesialrådgiver

(+47) 907 54 241
nils.vagstad@nibio.no

Sted
Ås - Bygg O43

Besøksadresse
Oluf Thesens vei 43, 1433 Ås (Varelevering: Elizabeth Stephansens vei 23)

Sammendrag

På oppdrag fra Vannområdeutvalget Morsa er det gjennomført beregninger av tiltakseffekter for gjennomførte tiltak innen spredt avløp, kommunale renseanlegg og avrenning fra jordbruksarealer i Morsa for perioden 2000 - 2006. Det er også sammenlignet endringer av kjemisk og økologisk status med teoretiske beregnete tiltakseffekter i nedbørfeltet. Fosfortilførsler fra spredt avløp er beregnet redusert med 57 % (fra 2,3 tonn pr år til 1,0 tonn pr år) fra 2000 til 2006. Basert på en ny beregningsmetode er tilførslene fra kommunalt avløp beregnet til 0,6 tonn pr år i 2005, mot 1,2 tonn pr år i 2000. Årlig fosfortap fra jordbruksarealer ble i 2000 beregnet til 12,2 tonn P, herav bakgrunnsavrenning 1,1 tonn P, det vil si en tilførsel på 11,1 tonn "antropogent" P fra jordbruksarealene. Effekten av endret jordarbeiding (3,7 tonn P), samt effekten av vegetasjonssoner og fangdammer (1,1 tonn P) gir en fosforavrenning fra jordbruksarealer på 6,3 tonn P i 2006. Totalt har jordbruket redusert tilførslene med 43 % i 2006 sammenlignet med nivået i 2000. Sammenlignet med overvåkingen viser de teoretiske beregningene at på tross av en middels til høy grad av tiltaksgjennomføring både innen jordbruk, samt kommunalt- og spredt avløp, er vannkvaliteten (basert på kjemiske parametre) fremdeles å anse som dårlig til meget dårlig i flere delnedbørfelt. Vannkvaliteten er klassifisert som meget dårlig i Hobølelva, Kråkstadelva og Veidalselva, dårlig i Mørkelva, Sæyvannet/Svinna, bekkefelt til Storefjorden og bekkefelt til Vanemfjorden, og moderat i Mjær. Det har vært noe forbedring i vannkvaliteten i flere delnedbørfelt både med tanke på kjemisk og biologisk tilstand, men fosfortapene fra både jordbruk og spredt avløp er i enkelte felt fremdeles svært høye, og flere tiltak bør iverksettes for å oppnå bedret vannkvalitet.

Sammendrag

Presentation at the scientific conference of the agrotechnical fair in Kielce: New Techniques and Technologies in Sustainable Agriculture.

Sammendrag

The challenges in providing sufficient food supply and drinking water to a rapidly growing world population are tremendous. Even more so, to meet these challenges without causing unacceptable pressures on the environment and the natural resources with subsequent risks of undermining the potential for feeding future generations. These questions, which basically deal with sustainability, should represent the framework for any development strategy in agriculture, irrespectively of whether the scale is global or local. The need for additional land and access to water represents key constraints in terms of meeting the expected increase in food demand, and would probably require a series of diverse development strategies, depending on both region and site-specific conditions. This presentation discusses different issues linked to the potential conflicts between increased food production in agriculture, and environmental impacts including food safety aspects. Contrasts will be exemplified by the two prevailing trends in agricultural practices; conventional farming practices based on extensive external inputs possibly also with the use of GM crops, and, organic agriculture based on the mineralization of external inputs into the production system. Strategies that may mitigate the pressures on the land and water resources are analysed in terms of quantitative as well as qualitative measures. A development strategy for sustainable agriculture would need to emphasis efficiency in terms of resources utilisation, and integrated approaches in terms of management strategies.

Sammendrag

The challenges in providing sufficient food supply and drinking water to a rapidly growing world population are tremendous. Even more so, to meet these challenges without causing unacceptable pressures on the environment and the natural resources with subsequent risks of undermining the potential for feeding future generations. These questions, which basically deal with sustainability, should represent the framework for any development strategy in agriculture, irrespectively of whether the scale is global or local. The need for additional land and access to water represents key constraints in terms of meeting the expected increase in food demand, and would probably require a series of diverse development strategies, depending on both region and site-specific conditions. This presentation discusses different issues linked to the potential conflicts between increased food production in agriculture, and environmental impacts including food safety aspects. Contrasts will be exemplified by the two prevailing trends in agricultural practices; conventional farming practices based on extensive external inputs possibly also with the use of GM crops, and, organic agriculture based on the mineralization of external inputs into the production system. Strategies that may mitigate the pressures on the land and water resources are analysed in terms of quantitative as well as qualitative measures. A development strategy for sustainable agriculture would need to emphasis efficiency in terms of resources utilisation, and integrated approaches in terms of management strategies.

Sammendrag

Quantifying P losses to surface waters at different scales and partitioning of the loads into P losses from point sources and diffuse sources are significant future challenges for river basin managers. The agricultural share of P losses to surface waters is, in many river basins, increasing and therefore becoming more important to quantify and analyse. The importance of phosphorus losses from agricultural land was analysed using monitoring data and two different models for 35 micro-catchments (50 000 km2). Average annual phosphorus loss from agricultural land in the micro-catchments varied from 0.1 to 4.7 kg P ha)1 and showed no relationship with the short-term P surplus on agricultural land. The average annual total P loss from agricultural land showed equally large variation in the 17 macro-catchments (0.1"6.0 kg P ha)1), but the range was less for the 10 larger river basins (0.09"2.0 kg P ha)1). The annual P loss from the 35 micro-catchments was greatest in the micro-catchments characterized by soil erosion and a high proportion of surface run-off as in the Norwegian catchments. The same pattern was true for the 17 macro-catchments where the model-simulated total P loss from agricultural land was greatest in the catchments in northern and southern parts of Europe. The main diffuse pathways for total P loads in the 17 macro-catchments were simulated with the MONERIS model. On average, soil erosion and surface run-off was estimated to have contributed 53% (4.1"81%), groundwater 14% (0.2"41.7%) and tile drainage water 3% (0"14.0%).

Sammendrag

Oversvømmelse av jordbruksarealer på grunn av flom i store vassdrag kan medføre avlingstap eller kraftig avlingsforringelse. På sikt er det et større problem når topplag og undergrunnsjord blir vasket vekk når for eksempel flomverk svikter, og store mengder sand sedimenteres på produktive jordbruksområder. Å bygge opp nytt jordsmonn med gode fysiske og kjemiske egenskaper er en stor utfordring, og det kan ta tid før den nye jorda gir normale avlinger. I denne artikkelen gir vi en oversikt over erfaringene som ble gjort etter flommen i Glomma og Gudbrandsdalslågen i 1995

Sammendrag

The Ministry of Agriculture and Food established in 1992 the Agricultural Environmental Monitoring Programme (AEMP) in Norway. The monitoring program is an important part of the overall strategy for sustainable development. One of the major and concrete objectives of the programme is to quantify and to document the diffuse nutrient losses from representative agricultural areas and production systems in different agro-ecological regions of Norway, and furthermore, to help generate adequate data and knowledge for policy support and for the implementation of appropriate environmental measures. The AEMP-programme also includes a component dealing with monitoring of pesticides, but this component is not described further in this paper. Bioforsk is in charge of the practical implementation of the program. This paper presents a brief description of the design and the structure of the program, various activities and routines that are applied and finally also a short summary of some major results in terms of measures nutrient losses. Similar programs as the Norwegian AEMP are established in Estonia, Latvia and Lithuania. These programs were established in close co-operation between Bioforsk and different research organisations in the Baltic countries. More information about the programs can be found in Vagstad et al (2001).

Sammendrag

The evaluation of water bodies "at risk" of not achieving the Water Framework Directive"s (WFD) goal of "good status" begs the question of how big a risk is acceptable before a programme of measures should be implemented. Documentation of expert judgement and statistical uncertainty in pollution budgets and water quality modelling combined with Monte Carlo simulation and Bayesian belief networks, make it possible to give a probabilistic interpretation of "at risk". Combined with information on abatement costs, a cost-effective ranking of measures based on expected costs and effect can be undertaken. Combined with economic valuation of water quality, the definition of "disproportionate cost" of abatement measures compared to benefits of achieving "good status" can also be given a probabilistic interpretation. Explicit modelling of uncertainty helps visualize where research and consulting efforts are most critical for reducing uncertainty. Based on data from the Morsa catchment in South-Eastern Norway, the paper discusses the relative merits of using Bayesian belief networks when integrating biophysical modelling results in the benefit-cost analysis of derogations and cost-effectiveness ranking of abatement measures under the WFD. Keywords: Benefit-cost analysis; Disproportionate costs; Eutrophication; Programme of measures.