| Main authors: | Ingrid Nesheim, Leah Jackson-Blake, Francois Clayer |
| FAIRWAYiS Editor: | Jane Brandt |
| Source documents: | »Oenema, O. et al. 2018. Review of measures to decrease nitrate pollution of drinking water sources. FAIRWAY Project Deliverable 4.1, 125 pp »Commelin, M. et al. 2018. Review of measures to decrease pesticide pollution of drinking water sources. FAIRWAY Project Deliverable 4.2, 79 pp »Velthof, G. et al. 2020. Identification of most promising measures and practices. FAIRWAY Project Deliverable 4.3, 72 pp |
One of FAIRWAY's major research themes is the identification and assessment of most promising measures and practices to decrease nitrate and pesticide pollution of drinking water supplies by agriculture (see »Farming practices: review and assessment).
Data and information collected from the Vansjø case study was used in the research tasks as described here. Nitrate, rather than pesticide, pollution is the main issue in this area.
| Contents table |
| 1. Measures to decrease nitrate pollution |
| 2. Effectiveness of nitrate and pesticide measures |
1. Measures to decrease nitrate pollution
In »Review of measures to decrease nitrate pollution of drinking water sources we describe how FAIRWAY built on insights and results gathered in EU-wide and global projects and studies. We provide an overview and assessment of the effectiveness and efficiency of measures aimed at decreasing nitrate pollution of drinking water sources. As part of the review, the Vansjø case study provided information about the measures that have been implemented in the local area.
| Name of measure | Reduced tillage |
| Target | Quality surface water resources |
| Description | Reduced tillage is the single measure that has the greatest effect with respect to reduced nutrient leakage. It contributes to reduced soil erosion and the loss of nutrients (N,P) and soil particles from the crop land to the river basin. |
| Mode of action | In Morsa, this measure alone has led to a reduction of nearly four tonnes of phosphorus per year. Reduced tillage also has important additional effects. |
| Expected effectiveness | Moderate: 10-25% decrease in concentration/load |
| Expected cost | Moderate: 10-50 euro per ha |
| Underpinning | Yes (> 5 reports) |
| Applicability | Yes (on more than 75% of the agricultural land) |
| Adoptability | Partly (on 25-75% of the addressees) |
| Other benefits | Plant residues on the soil surface protect the soil from rain and running water Increased content of organic material in the soil layer increases the stability of the soil aggregates Increased biological activity with subsequent improved soil structure in the soil layer. Reduced traffic on the areas leads to less risk of packing damage. |
| Disadvantages | Unknown |
| References |
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| Additional comments | Disadvantages or not; is often a consequence of how it is being done in practice. |
| Name of measure | Reduced (optimal) fertilization |
| Target | Quality surface water resources |
| Description | Reduced (or optimal) fertilization is an important measure. The Morsa/Vansjø Sub-River Basin organisation has contributed to changes in the national standards for phosphorus fertilizers for cereals and meadows. These have now been reduced by 25%. This results in reduced phosphorus content in soil over time and consequently reduced amount of phosphorus that is bound to particulate matter, as well as reduction in the amount of alloys available phosphorus. |
| Mode of action | Requires better planning of farm nutrient balances for individual fields, towards more precision farming. Selection of time, type of fertiliser and method of fertilisation are important. Soil tests should be conducted. Phosphorus index is a tool that helps estimate the risk of phosphorus (P) losses from agricultural fields. |
| Expected effectiveness | Low: 5-10% decrease in concentration/load |
| Expected cost | Low: < 10 euro per ha |
| Underpinning | Yes (> 5 reports) |
| Applicability | Yes (on more than 75% of the agricultural land) |
| Adoptability | Yes (more than 75% of the addressees) |
| Other benefits | Can increase yield if done in a precision-farming manner. Can reduce costs, in particular if commersial fertilisers are being used. |
| Disadvantages | None |
| References | Bechmann, M., Blicher-Mathiesen, G., Kyllmar, K., Iital, A., Lagzdins, A., Salo, T., 2014. Nitrogen application, balances and the effect on nitrogen concentrations in runoff from small catchments in the Nordic - Baltic countries. Agriculture, Ecosystems and Environment 198 (2014) 104 - 113. |
| Additional comments |
| Name of measure | Grass covered waterways |
| Target | Quality surface water resources |
| Description | Relatively small areas on a field can account for a very large part of the soil erosion (and associated nutrient losses), especially when a large amount of surface water seeks it way to lower and narrower parts of the fields . |
| Mode of action | The measure of grass covered waterways, which involves sowing grass in water-bearing and erosion-induced slopes, is a very important measure that is given high priority. Grass covered waterways are established in droughts where the water erodes. |
| Expected effectiveness | High: >25% decrease in concentration/load |
| Expected cost | Very high: >100 euro per ha |
| Underpinning | Partly (1-5 reports) |
| Applicability | No (on <25% of the agricultural land) |
| Adoptability | No (on <25% of the addressees) |
| Other benefits | Yes, contributes to landscape diversity other, namely substantively reduction in soil erosion. |
| Disadvantages | None |
| References |
Anne-Grete Buseth Blankenberg og Heidi A. Grønsten. Vegetasjonsdekke som tiltak mot tap av jord og fosfor (Vegetation cover as measure against soil and phosphorous losses) .BIOFORSK TEMA vol 9 nr 6 ISBN 978-82-17-01218-4 http://www.bioforsk.no/ikbViewer/Content/109019/Vegetasjonsdekke_AGB.pdf Peter Fiener and Karl Auerswald . 2017. Grassed Waterways. Ch. in Precision Conservation: Geospatial Techniques for Agricultural and Natural Resources Conservation, J. Delgado, G. Sassenrath and T. Mueller (ed.) ISBN: 978-0-89118-356-3, Published: June 16, 2017 |
| Additional comments | Reduces the amount of cropland. |
2. Effectiveness of nitrate and pesticide measures
The information about 34 different nitrate mitigation measures, implemented locally in 10 different FAIRWAY case studies, was collected and analysed. The measures were aggregated by type and the average/overall scores for effectivity, cost, applicability, and adoptability were assessed from the individual records and comments. See »Management practices that reduce nitrate transport - Results and discussion - Case studies.
Similarly, information about 17 different pesticide mitigation measures, implemented locally in 7 different FAIRWAY case studies, was collected and analysed. The measures were evaluated for their cost and effectiveness for reducing pollution of groundwater and surface water. See »Management practices that reduce pesticide transport - Results - Case studies
Note: For full references to papers quoted in this article see