Here is the text from this article:
"The Cambodian genocide was the systematic persecution and killing of Cambodian citizens by the Khmer Rouge under the leadership of Communist Party of Kampuchea general secretary Pol Pot, who radically pushed Cambodia towards an entirely self-sufficient agrarian socialist society."
Now let's read Stalin:
https://www.marxists.org/reference/archive/stalin/works/1906/03/x01.htm
"Let us first deal with the point that in introducing socialism, the Socialist-Revolutionaries want to begin with the countryside. Is this possible? Everybody knows that the town is more developed than the countryside, that the town is the leader of the countryside, and, consequently, every activity for socialism must begin in the town. The Socialist-Revolutionaries, however, want to convert the countryside into the leader of the town and to compel the countryside to begin introducing socialism, which of course is impossible owing to the backwardness of the countryside. Hence, it is obvious that the 'socialism' of the Socialist-Revolutionaries will be stillborn socialism."
Stalin wrote about the mistakes of the Socialist-Revolutionary Party, but it is also true of Pol Pot. Here we see that Pol Pot, with his agrarian socialism, has clearly departed from Marxism. I see no point in digging deeper into the subject now and parsing the whole wikipedia article.