%0 Journal Article %T POTATO PRODUCTIVITY OF DIFFERENT GROUPS OF RIPENESS, DEPENDING ON METHODS OF AGRO-MACHINERY CULTIVATION ON GRAY FOREST SOILS OF THE MIDDLE VOLGA STEPPE %A Chekmarev, P.. %A Gareev , I.. %A Vladimirov, V.P. %K potato, variety, productivity, calculated doses of fertilizers, quality indicators, starch, vitamin C, nitrates. %J Vestnik of Kazan State Agrarian University %D 2015 %N 10 %P 4 %I Kazan state agrarian University