The Ukrainian "Holodomor" was the mass starvation of Ukrainians and other ethnic groups perpetrated by the Soviet Union from 1932-33. Lianna Laberge, in her article "No One Else to Ask: Investigating the Ukrainian Holodomor," asserts that over 7 million Ukrainians starved to death during this time. Stalin, seeking to crush resistance to the implementation of collective farming in Ukraine and to pacify a nation whose loyalty he questioned, deliberately exacerbated famine conditions that had already come about as a result of Soviet farming practices. According to Robert Conquest in "The Harvest of Sorrow: Soviet Collectivization and the Terror Famine," Soviet grain requisitions from Ukrainian farms rose by about 1.7 million tons between 1932 and 1933 despite years of crop failures. Citizens attempting to flee were arrested and often forced to return home -- basically a death sentence given the widespread starvation that was happening there. Granted, agricultural productivity had been sharply declining in Ukraine since the implementation of collective farming in the late 20's, but the famine was almost certainly a result of state intervention. According to Hiroaki Kuromiya in "Stalin: Profiles in Power," crop yields were even lower in 1936 than in 1932, but there was no second famine. Basically, Stalin ordered Ukraine to be systematically starved in order to bring the population to heel.

There was an AMA with a Holodomor survivor too. https://www.reddit.com/r/IAmA/comments/12x8lc/iama_survivor_of_the_19321933_ukrainian_holodomor/

Hope that helps!