The production and import of fertilizer have previously been identified as the major source of three separate European environmental problems related to nitrogen compounds. In order to obtain a picture of the changes in the anthropogenic nitrogen flows needed for a solution, the effectiveness of several more radical interventions is estimated using Substance Flow Analysis (SFA). A selection of rigorous technical measures is expected to reduce the atmospheric deposition of N compounds to a level that seems acceptable for the EU as a whole, and will reduce the anthropogenic input of N compounds into the North Sea well below the agreed level of 50% of the present load. The third problem, the pollution of groundwater with nitrates, would remain unsolved. Resolution of this last problem requires radical changes in the agricultural sector, reducing agricultural output substantially. Two directions are explored by assessing the impacts of the extremes: termination of industrial fertilizer use to combat the problems at the source, and abolition of the entire stock-breeding sector to increase agricultural efficiency radically. These changes do contribute to a solution of the groundwater problem, but imply either greater dependence on imported food, or a major change in food consumption patterns, from animal towards vegetable products. The current EU population and diet are incompatible with the absence of environmental problems. The question then arises, how does acceptance of the draconian measures required to solve such an environmental problem weigh up against acceptance of the fact of having to cope with contaminated groundwater?

The European Union is faced with major environmental problems related to nitrogen (N) compounds. The origins of three such problems, the atmospheric deposition of N compounds, the leaching of nitrates to ground-water and the anthropogenic N-input to the North Sea, are investigated by means of a Substance Flow Analysis (SFA); the reference year is 1988. Although the problems occur at various scales and have varying direct causes, food production and consumption together are the main responsible sectors, and the production and import of fertilizer appear to be the major ultimate sources in all three cases. Measures to combat these problems have been agreed to in various international frameworks: the European Community, the International North Sea Conference and the Rhine States Conference. These measures include technical emission reduction for acidifying compounds resulting in a 30% emission reduction; extension of the sewage treatment network and application of denitrification with 50% effectiveness; and introduction of measures directed at efficiency increase and emission reduction in agricultural practice in 10% of the agricultural area. The recent changes in the Common Agricultural Policy (CAP) are not expected to lead to significant changes in N flows. Assuming full implementation, an almost sufficient 45% reduction is expected for the anthropogenic nitrogen input into the North Sea. The atmospheric deposition of nitrogen compounds will be reduced by approximately 20%. The leaching of nitrates to the ground-water is expected to remain at the current level or even to increase a little. In all, these measures are conducive to solving, but do not satisfactorily solve, the three problems, mainly because the ultimate origins of the problems are not sufficiently influenced and measures therefore inevitably result in a shifting of problems.