Management practices that reduce nitrate transport
| Main authors: | Mart Ros, Gerard Velthof, Oene Oenema, Meindert Commelin, Susanne Klages, Linda Tendler, Jenny Rowbottom, Isobel Wright, Donnacha Doody, Luke Farrow, Birgitte Hansen, Morten Graversgaard, Irene Asta, Andrej Jamsek, Katarina Kresnik, Matjaz Glavan, Jean-François Vernoux, Nicolas Surdyk, Christophoros Christophoridis, Kate Smith, Irina Calciu, Sonja Schimmelpfennig, Hyojin Kim, Piet Groenendijk. |
| FAIRWAYiS Editor: | Jane Brandt |
| Source document: | »Ros, M. et al. 2020. Identification of most promising measures and practices: 2. Reduction nitrate transport from agricultural land to groundwater and surface waters by management practices. FAIRWAY Project Deliverable 4.3, 72 pp |
For a description of the background issues concerning the agricultural use of nitrates and their contamination of drinking water supplies see
»Background and objectives of the review
In this section of FAIRWAYiS we review the effectiveness of management practices for reducing NO3 losses to ground and surface water resources. We combine
- a synthesis of existing review papers,
- a meta-analysis of available data from literature and
- practice based knowledge from nine case studies across Europe.
»Materials and methods
»Results and discussion
Our main conclusions are:
- A review of existing meta-analyses and quantitative reviews showed that there is a lot of information available on the effectiveness of measures to reduce NO3 losses to ground and surface waters. In particular the use of cover crops, (nitrification) inhibitors, and biochar has been well documented, often in relationship with other N parameters, such as N2O emissions or soil N transformations.
- The use of non-legume cover crops appears an effective way to reduce NO3 losses. This effect is often diminished when legumes are included. Application of DCD also seems to be effective as a measure and cost-benefit analyses show that this can be profitable. For other measures, such as biochar and changes in tillage practices, the results differ.
- The success of the implementation of a measure often varies per farm and per location. It is subject to differences in topography, climate, and other farm management practices. Farm-tailored solutions are therefore likely to yield result. This is illustrated by the large variety of measures proposed by the case study experts and the differences in applicability.
- Implementation of measures to reduce NO3 losses should not only consider the effectiveness, and costs, but also the adoptability and possible (unwanted) side-effects. While some measures may for example decrease NO3 and N2O losses, they could increase NH3 volatilization. These effects of the measures on the N cycle and possibly those of other nutrients should be considered. This is true for measures at both the field and farm scales.