Farmland appears when Dirt is tilled by a Hoe. It is the only block Seeds, Carrots and Potatoes will grow on. The ideal condition for Farmland is near Water; this will make whatever is planted grow much more quickly. In addition, if Water is not nearby, the Farmland block will revert to dirt if left without a crop for too long.
Due to the abundant Slimes on superflat worlds, Villager crops may be trampled by their constant hopping long before the player reaches them.