Minecraft wiki entry for Crop_farming, associated text: Instead of going for a 9×10 expansion, it is also possible to stay in the 9x9 field (11x11 fenced) footprint by adding four water dispensers on the four corners of the fence. This variation takes more dispensers to make, but all products fall into the water hole for easy collection. When you make the farm vertical, a sign can be used to contain the water while allowing the items to fall through to the bottom layer, where a hopper may lie.