It is quite certain, however, that energy saving investments must be directed, first and foremost, at ammonia production plants, which are the highest consumers in the natural gas-fertilizer chain. ###>Il est certain que les investissements d'économie d'énergie doivent prioritairement porter sur les unités de production d'ammoniac, les plus consommatrices de la chaîne gaz naturel-engrais.