Bio farms are resource buildings in Tropico 4: Modern Times that take the place of farms. They take up much more space than old farms do and employ fewer people, but they produce multiple crops at a time at a much higher rate. Depending on the work mode, these farms can create large quantities of either corn, food crops (bananas, pineapples, papayas) or cash crops (tobacco, sugar, coffee). In addition, they also grow corn on the side, regardless of work mode. It is an efficient use of workforce to modernize your island's agriculture with bio farms when they become available, but they place a heavy load on your teamsters, due to the volume of crops they create, so it is ideal to not have too many, either. Like regular farms, these will decrease the beauty around them.