TY JOUR TI IMPACT OF CALCULATED DOSES OF FERTILIZERS ON PRODUCTIVITY AND QUALITY OF EARLY-MATURING POTATO OF SPRINT VARIETY IN THE FOREST-STEPPE OF THE MIDDLE VOLGA REGION KW potato KW planned productivity KW calculated doses of fertilizers KW dry substance KW starch KW crude protein KW vitamin C KW nitrates. JO Vestnik of Kazan State Agrarian University AU Gareev , I.. PY 2016 IS 11 PB Kazan state agrarian University