Abstract <p>The article presents a quantitative assessment of the impact made by tariff policy measures on global markets for phosphorus-containing mineral fertilizers: monoammonium phosphate (MAP) and diammonium phosphate (DAP). The analysis is based on a mathematical model of spatially distributed markets. A scenario analysis of five alternative development options was also conducted including a baseline scenario of continuing current trends, two scenarios of tightening tariff policy, and two scenarios of its liberalization in the United States and Europe. It is shown that a reduction in tariffs on the European market benefits all DAP producers and MAP suppliers, whereas the American scenario favors MAP producers while simultaneously shifting DAP producers to less profitable markets.</p>