The article is devoted to the dynamics of nitro-gen availability in the planting area of different vari-eties of potatoes in a meadow-chernozyom soil (Alaya zarya, Svitanok, Kormilets, Zekura and Rosara) under cultivation on meadow-chernozyom clay loamy shallow soils of Western Siberia. Field experiments were carried out within 2 years from 2008 till 2010 in the experimental field of Omsk SAU. Experiments were two-factor. The recurrence was three-times. The scheme of potatoes plant is the following: 70×30 cm tubers weighing 80-100 g. The experimental plot size was 9.6 m2. The total test plot territory was 510 m2. By the time of har- vesting the studies concerning the dynamics of available nitrogen accumulation in the planting area (N-NO3, kg/hectare) showed the following data: the highest rate of nitrogen release during the growing season was found out in varieties Alaya zarya and Zekura, as well as the variety of potato Kormilets totals 78.2 % out of its peak level. The research resulted in the quantities of available mineral nitro-gen accumulation in soil (Nm) in the planting area that determine the potato's ability to take nitrogen from the soil (measuring and control appliances). The actual nitrogen balance in soil and supposed one adjusted for the needs of potato varieties in nitrogen and the ability of nitrogen taking from the soil according to the measuring and control appli-ances match. The obtained results were crucial while attempting to diagnose nitrogen nutrition, predicting the volume of the crop and the estima-tion of fertilizer doses for potatoes of specific varie-ties cultivated in a forest-steppe zone of Western Siberia.