You might find it interesting to bear in mind some of the context of Russia at the time this excellent story was written. In 1861, Tsar Alexander II ordered the emancipation of Russian serfs, which was clearly a good thing, because before this serfs were slaves of landowners and could be bought or sold and were not allowed to own property. Tolstoy wrote this story after the serfs had experienced 25 years of freedom. Tolstoy is of course not arguing for a return to the way things were, but this story, with its focus on greed and materialism, does question whether the progress of the peasants had actually brought with it negative aspects.
You also might want to consider the title and its importance in relation to the theme of greed. Firstly, note the deliberate use of the word "need" at the end, rather than "want." If it were "want," Pahom clearly shows in the story again and again that there is no end to the amount of land that a man wants. Each new land purchase only fuels his desire to have more land. The question of the title is answered ironically only at the end of the story, when we find that the only land a man "needs" is enough to bury him:
His servant picked up the spade and dug a grave long enough for Pahom to lie in, an dburied him in it. Six feet from his head to his heels was all he needed.
Greed is shown to have resulted in Pahom's death as he sacrificed his life in the attempt to gain ever greater quantities of wealth.