Abstract: The invention discloses a circle irrigation system providing improved chemical application control within said system by varying the height from the chemical application nozzles to the application area, spacing of the nozzles along the boom, delay switches for movement of the towers relative to turning the nozzles on and off, diaphragms providing quick cycling of the on-off of the nozzles without leakage, pressure valves for varying the nozzle pressure within a boom and means for mixing and monitoring a plurality of chemicals within water and eliminating the possibility of back flushing the chemical mixture into the water supply.