Basing upon examined linear functional relations the author presents interdependences between winter wheat efficiency and mineral fertilizing with particular NPK components at 10 ha and over 10 ha farms in Middle-East Macroregion within 1990–2001. It was possible to measure both average and marginal productivity for statistically important mineral fertilization with NPK components in winter wheat tillage in the surveyed farms. The survey showed similarity in average productivity level and character but marginal productivity revealed a baseless increase phosphorus fertilization, twice higher marginal productivity of fertilization with potassium towards nitrogen and relatively low marginal productivity of fertilization with nitrogen but very stable even at low levels of fertilizing.