Main authors: Berit Hasler, Ingrid Nesheim, Morten Graversgaard, Susanne Klages, Doan Nainggolan, Claudia Heidecke, Luke Farrow, Isobel Wright, Gerard Velthof, Sandra Boekhold
Editor: Jane Brandt
Source document: »Hasler, B. et al. (2021) Identification of cost-effective and coherent management models for drinking water protection in agriculture. FAIRWAY Project Deliverable 6.4R 55 pp


The analyses in this section of FAIRWAYiS are based on literature review, including review of farm surveys, interviews with experts and stakeholders including feedback described in »Governance arrangement in case studies and policy documents.

The approach therefore provides the opportunity to draw some general conclusions related to best management practices related to nitrogen abatement measures in European countries, and more specificly to catch crops as a nitrogen leaching abatement measure. The focus has been on nitrogen, while pesticides measures are discussed in relation to nitrogen measures and coherence. The approach also provide background for more specific conclusions based on the comparative comparison between the six European countries, whereas there are EU member states (DK, DE and NL), EFTA state (NO) and countries outside these (EN and NI), but where similar environmental regulations exists.

As mentioned in »Overview and assessment of measures and instruments, we have based the comparison on literature, policy documents, and expert knowledge and to some extent on interviews with farmers, agricultural advisors different levels and agronomists. There seem to be similarities across countries in how farmers perceive this measure and cultivation of catch crops, but also differences which can be explained by differences in production, climate, regulation and history.

For the analysis and assessment, four criteria have been identified for the assessment of measures and policy instruments. They include

  • pollution control effectiveness,
  • cost-effectiveness,
  • efficiency, and
  • coherence and incentives in place.

Based on the studies reviewed and evidence from the FAIRWAY case studies, the conclusion is that catch crop cultivation is one of the most cost-effective measure to reduce nitrogen leaching compared to measures such as nitrogen fertilizer reductions and wetland restoration (Konrad et al 2014, Hasler et al 201; Gooday et al 2014). Other studies find that catch crops are not cost-effective if both nitrogen and phosphorus are regulated at the same time, but this finding rests on an assumption that catch crops do not reduce phosphorus losses.

One reason that catch crops are such an important measure in EU agri-environmental policy is that catch crops can be implemented at relatively low costs compared to many other measures, and with relatively high environmental effects. The costs for the individual farmers can be substantial, but that is also the case for other measures to reduce nitrogen leaching. The question is therefore who are covering the costs for seeds and costs associated with additional cultivation, as well as potential loss of yields. The studies reviewed indicate that subsidies for catch crops are important as incentives for uptake of this measure, but also that the required level of compensation to enroll voluntarily implementation differs between both farm types and regions. In Denmark, an explanation can be the need for crop rotation changes from winter crops to spring crops, in order to be able to establish catch crops, or risk aversion.

The reviewed surveys of farmers’ adoption of catch- and cover crops indicate that there are barriers towards efficient implementation of these measures, and that understanding these barriers might improve farmer adoption rate. Overall, a number of studies indicate large variations in how farmers express their willingness to accept implementation of catch crop cultivation.

A rich literature exists on cover crop implementation in the US, and a growing number of studies have also been made in Europe, focusing on catch crops, farmers incentives, preferences and barriers, policy instruments and mechanisms to implement catch crops. Some studies have also produced results to inform about the barriers and potentials to achieve implementation effectively and to the least costs.

The review of farmer perceptions of motivation and constraints of implementing catch crops, shows that several factors are seen as economic constraints. The risk of reduced yield, the increase costs of pesticides, costs of seeds, of equipment and labour are referred to and, in some countries, regulations can result in incompatible management practices with regard to main crop and catch crop. Though a few studies also refer to some farmers expecting increased yield, and reduced costs of pesticides, the same studies also find that farmers experience reduced yield and increase costs of pesticides. There is furthermore an uncertainty and risk in the degree of economic impact associated with catch crops (e.g. Smit et al 2019).

The answer as to whether catch crops is a best practice measure is that yes, it is a cost-effective measure, but there are several barriers to farmers implementation from risk of yield loss which should be included in the costs. There are also potentials, as the measure is relatively simple to include in the rotation and it does not require pemanent installations or changes to the production and planning.

In the detailed study of 6 FAIRWAY case studies, the factors that affect uptake of catch crops as a nitrogen abatement measure in farming systems in NO, EN, NI, NL, DE (Lower Saxony) and DK were assessed, as well as how do farmers preferences, attitudes and risk considerations explain the uptake of the measure.

Barriers affecting uptake were identified. From the country descriptions and comparison between the countries barriers can be identified related to farmer uptake. Main barriers are attributed to cultivation, mainly related to expected yield reduction effects of the main crop, but also to the establishment and growth of the catch crop, costs of seeds and the effects of the timing of cultivation operations. Challenges related to choice of catch crop species, resilience, influence on weeds and diseases, climatic effects and hydrology (dry or wet soils), establishment of subsequnt crops are also identified. A barrier has also been identified related to the level of knowledge on benefits of the this measure and the cultivation practices.

There are also indications of potential barriers related to the regulatory approaches applied in the countries, where the uptake seems lower in the countries where few policy incentives are present (or where there are policies but choices allow farmers to avoid catch crops).

From our comparison of the cost-effectiveness of catch crops we can draw the conclusions that there are differences among countries in the need for additional cultivation practices (ploughing, seedbed preparation), and that the same factors affect the farmer implementation. There are also differences in farmers’ and administration /researchers’ expectations regarding the catch crop effects for increased or reduced yield of the main crop. Furthermore, there are differences in the knowledge farmers have related to cultivation opportunities related to catch crops, and also on the effects on yields and on leaching.

Even though the EFA (Ecological Focus Areas) and the Greening requirement in EU CAP Pillar 1 have been criticized by many, e.g. the European Court of Auditors (ECA 2017) and some ex ante research studies (e.g. Louhichi, et al. (2018), the greening requirement and catch crop implementation seems to have potential to be effective in terms of a large uptake among farmers. If the expected effects on nitrogen leaching holds, the measure is effective. The research and surveys reviewed here also indicate that farmers are familiar with this regulation.

The conclusion is that lessons can be learnt and transferred from catch crops to other policy measures.

The barriers related to farmers’ uptake of catch crops are to a high degree connected to the

  • Risk of yield effects, which might be both positive and negative, but the uncertainty is important
  • Operation costs, e.g. on seeds
  • Timing effects

It is apparent that both differentiated compensation of the costs and knowledge sharing and advice are important factors for this measure to be successful, and this is also the fact for other abatement measures. Important learning points from this study for other policy measure therefore refers to the need to tailor regulations and compensation mechanisms, and customize advisories to local conditions as the differential climate and growing conditions impact farmer agricultural practices and their economic situation. Furthermore, the understanding among farmers is essential, both regarding the benefits of catch crop for the environment, and the potential win-win effects for agricultural production, as well as possibilities for changes in practice.

We have also identified potential conflicts between the implementation of catch crops for nitrogen abatement and pesticide regulation, and these kinds of conflicts are important for coherency between policies.

The indication that a range of policy instruments for implementation increase uptake and awareness is also an important lesson learnt which can be of importance also for other policy measures and areas. The mix between mandatory requirements and voluntary uptake with use of subsidies seem to be working in many of the countries, but more research into the potential conflicts and complexity caused by these mixes will shed more light on this.

As discussed, the analyses in this report are based on literature review, policy documents and expert knowledge, and to some extent interviews with farmers. Farm surveys, as performed in some of the reviewed studies, can be used to retrieve more information on how farmers perceive regulation, and the related potentials and barriers for efficient implementation. This type of investigations can be done both ex post, i.e. after implementation, and ex-ante, i.e. prior to design and implementation of new regulations. The approach therefore gives the opportunity to draw some general conclusion related to catch crops as a nitrogen leaching abatement measure in European countries, as well as more specific conclusions based on the comparative comparison between the six European countries, whereas three are EU member states, and three are outside EU but similar regulations exists.



For full references to papers quoted in this article see



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