The aim of fertilization is to optimise crop production in order to sustain a growing global population. At the same time, this needs to be balanced with meeting environmental legislation associated with the EU Nitrates Directive (91/676/EEC) and the EU Water Framework Directive (2000/60/EC) in particular.

The synthesis presents the responses of 23 EJP Soil participating countries on recommendations for harmonizing methodologies for fertilization guidelines across regions. All participating countries have fertilization guidelines, which are produced by their country and specific to their country. In most countries the fertilization guidelines are managed by a committee of stakeholders such as researchers, government representatives, farm advisors and farming representatives.

The synthesis involved a stocktake questionnaire enquiring information about six main sub-objectives:

1. To complete a stocktake of current fertilization guidelines across regions within the EJP SOIL.
2. To identify key variables in directing these guidelines, e.g. climate, soil, cropping system, nutrient loss.
3. To identify synergies, similarities and differences between systems.
4. To assess the potential for harmonization of methodologies and barriers to harmonization.
5. To identify stakeholders involved in formulating fertilization guidelines.
6. To evaluate the importance of knowledge transfer and community engagement.

The stocktake study revealed that there are a number of different soil tests available for measuring specific nutrients, and the tests used vary widely between countries, and between neighbouring countries within the same environmental zone, and regionally within the same jurisdiction. Differences in soil tests are necessary due to this huge spatial variation in soil types and soil properties both within an individual country and between countries.

Harmonizing data  will be challenging 

Harmonizing data between soil types, different analysis methods, different crop types, climate and management will be extremely challenging and perhaps impossible due the differences in soil type and agro-ecosystem variations.

Still, there is general agreement that a more centralised approach to fertilization guidelines across the EU would be advantageous. The report suggests that it may not be necessary to have a detailed knowledge of practices outside ones immediate region. However, some awareness of general practices and knowledge exchange for tackling environmental issues would be desirable. The sharing of ideas and knowledge around precision agriculture technology was widely specified as an area through which shared learning would be beneficial for future farming.

A more harmonized approach to fertilization practices between countries will benefit farmers by increasing knowledge around nutrient management practices. This includes sharing information and ideas in relation to nutrient sources and new innovative technology that could help improve farm efficiency and sustainability.

Highlights challenges and provides suggestions for moving forward

In addition, the report suggests that it may be useful to re-assess the soil analytical methods currently used. While fertilization guidelines are based primarily on agronomic need per crop and are specific to each soil type, the growing importance of environmental issues and the need to minimise nutrient loss may necessitate soil tests, which quantify the risk of nutrient loss within particularly sensitive zones, along with maintaining agronomic performance.

 This report is important for policymakers, in light of the Farm to Fork Strategy, which has set the ambitious target of reducing nutrient losses by at least 50% and reducing fertilizer use by at least 20% by 2030. This will only be achieved by applying balanced fertilization and sustainable nutrient management, while also implementing and enforcing environmental and climate legislation. A committed and unified approach to farm nutrient management will be required, which will involve sharing of knowledge and implementation of technology such as precise fertilization techniques and EU space technologies. This report highlights the challenges in implementing a harmonized approach to fertilization but also identifies the benefits and provides suggestions for taking this forward.