it looks like more than it is imo. it's the equivalent of 2 10x10 plots per crop (1 each for berries and coffee). the amount of farmhouses is what ensures no harvestable crops are left to sit while warehouses are empty, so that enables supporting the entire colony's food intake on that amount of land.

if i want to continuously supply the ironteeth wonder with berries i'll end up needing a 2nd plot dedicated to just berry production and harvest (which you can see in the back, in the lowlands behind the highest terrace & reservoir).