Inga Greipsland

Research Scientist

(+47) 974 10 477
inga.greipsland@nibio.no

Place
Ås F20

Visiting address
Fredrik A. Dahls vei 20, 1430 Ås

Abstract

Diffuse phosphorus loss from agricultural fields is an important contributor to the eutrophication of waterbodies. The objective of this study was to evaluate a pilot project for the implementation of mitigation measures to reduce P losses. The pilot project is situated in southwestern Norway and, covers a 14-year period (2004–2018). It included data on the implementation of mitigation measures and water quality monitoring for six small catchments. The mitigation measures consisted of no tillage in autumn, reduced P fertilizer application, grassed buffer zones, and sedimentation ponds. Extra efforts were made to reduce diffuse P losses during the period from 2008 to 2010. The project comprised economic incentives, an information campaign, and farm visits. Data from 2004 and 2010 showed that the use of P fertilizer during this period decreased by 80% and the area of no-till in autumn increased in all six catchments and covered 100% of the area in three of the six catchments in 2010. However, with decreased economic incentives after 2010, the degree to which the mitigation measures were implemented was reversed; P-fertilization increased, and no-till in autumn decreased. No significant effects of mitigation measures on total P and suspended sediment concentrations were detected. We conclude that economic incentives are necessary for the comprehensive implementation of mitigation measures and but that it is not always possible to show the effect on water quality.

Abstract

Measures designed to control erosion serve two purposes: on site (reduce soil loss) and off site (reduce sediment delivery to streams and lakes). While these objectives often coincide or at least are complementary, they could result in different priority areas when spatial planning is concerned. Prioritising for soil loss reduction at the field level will single out areas with high erosion risk. When sediment flux at the catchment scale is concerned, sediment pathways need to be identified in ex ante analyses of soil conservation plans. In Norway, different subsidy schemes are in place to reduce the influx of solutes and sediments to the freshwater system. Financial support is given to agronomic measures, the most important of which is reduced autumn tillage where areas with higher erosion risk receive higher subsidies. The objectives of this study are (1) to assess the use of an index of connectivity to estimate specific sediment yields, and (2) to test whether conservation measures taken in critical source areas are more effective than those taken at where erosion risk levels are the highest. Different modelling approaches are combined to assess soil loss at catchment level from sheet and gully erosion and soil losses through the drainage system. A calibration on two parameters gave reasonable results for annual soil loss. This model calibration was then used to quantify the effectiveness of three strategies for spatial prioritisation: according to hydrological connectivity, sheet erosion risk level and estimated specific sediment yield. The latter two strategies resulted in a maximum reduction in total soil loss due to reduced autumn tillage of 10%. Both model performance and the effectiveness of the different prioritisation strategies varied between the study catchments.

To document

Abstract

From 2017, the Norwegian River Monitoring Programme (Elveovervåkingsprogrammet) replaced the former RID programme “Riverine inputs and direct discharges to Norwegian coastal waters” which had run continuously since 1990. The present report provides the current (2017) status and long-term (1990-2017) water quality trends in the 20 rivers included in the main programme.

Abstract

The moisture status of the upper 10cm of the soil profile is a key variable for the prediction of a catchment's hydrological response to precipitation, and of pivotal importance to the estimation of trafficability. Prediction, and even mapping, of topsoil water content is complicated, not in the least because of its large spatial heterogeneity. In IRIDA, an EU/JPI project, measurements, models and weather predictions will be applied to estimate the soil moisture status at the sub-field scale in near-real time. The project is in its early stages, during which the relevant parameters will be selected that will allow for soil moisture mapping on agricultural fields at a 10 m resolution.

To document

Abstract

Riverine inputs and direct discharges to Norwegian coastal waters in 2016 have been estimated in accordance with the OSPAR Commission’s principles. Nutrients, metals and organic pollutants have been monitored in rivers; discharges from point sources have been estimated from industry, sewage treatment plants and fish farming; and nutrient inputs from diffuse sources have been modelled. Trends in riverine inputs have been analysed, and threshold concentration levels investigated.

Abstract

Climate scenarios for Norway predict an increase in temperature, a longer growing season and more precipitation in most parts of the country (Hanssen- Bauer et al., 2015). More precipitation will likely have a negative effect on water quality because of the increased fluxes of nutrients like phosphorus (P) and nitrogen (N) into rivers and lakes. (Deelstra et al, 2011). Higher water temperatures are favorable to cyanobacteria, which could grow faster and create toxic waters. Even today, Norway experiences large problems related to heavy precipitation; for instance flooding, erosion, nutrient loss and damage to infrastructure. If precipitation continues to increase, the need for more or more effective mitigation measures in agriculture would become necessary.

Abstract

Norway has adopted the Water Framework directive and intends to achieve good ecological status in all water bodies by 2021. The environmental condition of Norwegian rivers and lakes are good compared to those in most other countries in Europe. A preliminary survey of the status of all Norwegian water bodies shows that around 50 % probably will meet the EU objectives/requirements for the freshwater environment, while around a quarter are at risk with regards to the requirements (Snellingen Bye et al., 2010). For the remaining water bodies, data are not available or their status is uncertain. Agriculture has been identified as the third most important factor influencing the status of Norwegian fresh water bodies.

To document

Abstract

Riverine inputs and direct discharges to Norwegian coastal waters in 2015 have been estimated in accordance with the OSPAR Commission’s principles. Nutrients, metals and organic pollutants have been monitored in rivers; discharges from point sources have been estimated from industry, sewage treatment plants and fish farming; and nutrient inputs from diffuse sources have been modelled. Trends in riverine inputs have been analyzed, and threshold concentration levels investigated.

To document

Abstract

Riverine inputs and direct discharges to Norwegian coastal waters in 2014 have been estimated in accordance with the OSPAR Commission’s principles. Nutrients, metals and organic pollutants have been monitored in rivers; discharges from point sources have been estimated from industry, sewage treatment plants and fish farming; and nutrient inputs from diffuse sources have been modelled. Trends in riverine inputs have been analysed, and threshold concentration levels investigated.