The Project

The Fertilizer Ordinance (DüV) regulates the good professional practice of fertilization in Germany and thus implements the EU nitrate guideline. The EU provides with the Nitrates Directive that the good professional practice in agriculture must be respected in order to reduce the nitrate pollution of ground and surface waters.
The current nitrate report by the Federal Environment Ministry shows that the nitrate problem is particularly pronounced in areas with intensive animal husbandry. However, N-excesses or too high nitrate concentrations in ground water are also observed in the regions with intensive vegetable cultivation. There is still a need for action in the field of vegetable production.

Under the conditions laid down in the amended DüV, vegetable growers must partly adapt their fertilization strategies, production systems, labor and company organizations so that they can continue to produce legal and economic production in the future.

At the initiative of the Federal Ministry of Food and Agriculture, the model and demonstration project began in early 2016. This interregional and interdisciplinary project is intended to expand the regional consulting for the implementation of the amended DüV. Key features of this project are:

Consistent use of knowledge and knowledge
The N-Expert System, developed at the Leibniz Institute for Vegetable and Ornamental Plants (IGZ), forms the basis for the fertilizer recommendations for all participating farms. The algorithms and data used in the N-Expert system reflect the state of knowledge for the calculation of field specific fertilization recommendations for vegetables. They are based on the results of national and international research projects as well as on the expertise of the national working group „Fertilization of field vegetables“, in which fertilizer producers and scientists work together. The N requirements for vegetables, which are binding with the amended DüV from 2017, are based largely on the recommendations of this working group.

An implementation of the DüV in farms with very different production systems and company organizations
The provisions of the Ordinance apply equally to all enterprises over two hectares of usable area. But the different operating structures require different approaches to integrate the regulations of the amended DüV into the production systems and company organizations. The choice of farms from three different regions ensures that the farms involved reflect the whole range of vegetable-producing plants, in particular with regard to the size, type and variety of the products and the marketing channels.

The regions and employees involved are:

The Knoblauchsland with very small-scale structures and a high proportion of direct marketing (Andreas Schmitt and Dr. Alexander Dümig, AELF Fürth, Anton Offenberger, Vegetable Producer Ring Knoblauchsland),

The Vorderpfalz with very large operational structures and indirect sales (Joachim Ziegler and Esther Paladay, DLR Rheinpfalz),

The Lower Rhine Area with medium-sized enterprises and mainly indirect sales (Manfred Kohl, Christine Lessmann and Dr. Karsten Lindemann-Zutz, LWK NRW).

Comprehensive cross-company cost-benefit analysis
The economic accompanying research is carried out by the Thünen Institute for Business Management (Dr. Hildegard Garming and Hanna Homeister). Operational costs and benefits of N-mitigation measures are assessed economically and the environmental benefits are assessed by the generation of N-balance sheets.

Network building and transfer of knowledge between important vegetable farming regions in Germany
Project meetings and workshops are intended to promote the exchange between the farmers, consultants and scientists involved in the project, thereby increasing and spreading the knowledge about the problems and problem solving in the other regions. During the duration of the project, informal workshops on information exchange are organized in small groups of project workers and managers. These workshops are used to transfer knowledge into practice and to discuss the results with the operations managers, who were not directly involved in the model and demonstration project.

The project is coordinated by the IGZ (Dr. Carmen Feller and Dr. Matthias Fink). Project sponsor is the Federal Institute for Agriculture and Food (BLE).
The common goal of all stakeholders is to demonstrate in a model way how to solve problems in the implementation of the Fertilizer Ordinance under practical conditions. In addition, further approaches contributing to the reduction of N losses are demonstrated under practical conditions, e.g. Irrigation control and crop rotation planning.
The results of the economic accompanying research will help to objectify the discussion about the effort and benefits of N-mitigation measures.