Abstract: Described is an irrigation system for large greenhouses including rails, an irrigation carriage including at least one irrigation bar equipped with suitable nozzles, a primary hose connected or connectable to the irrigation carriage and a secondary hose connected or connectable to the irrigation carriage. The irrigation system also includes a recirculation wheel configured to keep the primary hose and secondary hose taut during a sliding of the irrigation carriage and defining a first sliding channel and a second sliding channel configured, respectively, to receive at least partly the primary hose and the secondary hose so as to maintain sliding axes of the primary hose and secondary hose parallel to each other and lying on a same sliding plane.