Agricultural nitrogen use in selected EU countries. A comparison of N recommendations, and restrictions in response to the EU Nitrates Directive

The use of N in EU countries is subject to constraints as given in the Nitrates Directive (ND). Member states must define Codes of Good Agricultural Practice (voluntary measures) for their whole national territory, as well as designate Nitrate Vulnerable Zones (NVZs) where the risk of nitrate pollution would be high if actions prescribed in the ND were not taken. With specific reference to the designated NVZs, so-called Action Programs (APs) have to be established which contain mandatory measures in order to meet the objectives of the ND. For some countries, APs include N-application standards: explicit limiting values to N inputs. Central to Good Agricultural Practice (GAP) are the fertilizer recommendation systems, which reflect crop N requirements. Recommendations are the starting point for fertilizer planning – a required element of Codes of GAP as prescribed by the ND. They have also served as a reference in those countries where N-application standards were introduced. Another required element in Codes of GAP is the specification of periods when fertilizer application is inappropriate (closed periods). Finally, the fertilizer value of manures is required both for fertilizer planning (GAP) and to assess room for supplemental fertilizer inputs within set N-application standards. These elements together (recommendations, application limits, closed periods, and fertilizer equivalents) constitute the core of rules and regulations in the respective APs and Codes of GAP. Details of these elements, including numerical values, differ between countries. This reflects, in part, differences in biophysical and socio-economic production conditions. To provide a broader basis for justifying rules and numbers for adoption in APs and Codes of GAP, the study documented here compares recommendations and the various restrictions on N use among selected ‘neighbouring’ countries. The study is confined to Flanders, Denmark, Germany, France and The Netherlands. As for major crops, grassland, maize, potatoes, sugar beets, winter wheat, summer barley and onions are addressed.