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Climatic and geographic factors limit Russia’s agricultural activity to about 10 percent of the country’s total land area. 1_______. In the European part of Russia, the most productive land is in the Central Chernozem Economic Region and the Volga Economic Region, which occupy the grasslands between the Ukraine and Kazakhstan. 2_______. In Siberia and the Far East, the most productive areas are the southern regions. 3_______. The last expansion of cultivated land occurred in the late 1950s and early 1960s, when the Virgin Lands program of Nikita Khrushchev opened land in southwestern Siberia (and neighboring Kazakhstan) for cultivation. 4_______.