At first farming isn't something the villagers have figured out how to do so they have to subsist on berries from the berry bush. After they've got some tech-skill in farming (gained through spending time at the research table, and highly motivated by the tremendously high diet of fiber from living on just berries - can you EVEN imagine?!?) they'll figure out that they can actually work the land and get crops to grow.

I hope I haven't said too much.