Most agriculture is done intensively in closed, hydroponic systems.
You find hydroponic farms either in multiple layers underground, or in glass highrises, acting as greenhouses, with mirror systems bringing in the maximum amount of sunlight. Hydroponics are chosen in order not to damage the natural environment. Traditional farming is really much, much too expensive, when one takes the overall system into consideration. Hydroponic farms are closed systems where many of the resources are recycled indefinitely, and where yields are maximized per unit of space. Individuals and small communities might well do more traditional cultivation of open land adjacent to their living space.