An irrigation system includes a control arrangement which receives field information relating to an area to be irrigated and source information relating to one or more water sources which supply water to the irrigation system. The control arrangement optimizes an irrigation plan based on the field information and source information and then controls one or more irrigators in accordance with the plan. The control arrangement may pulse valves positioned on the irrigator on and off in order to control the amount of water applied to the land by individual outlets on the irrigator. Latching valves may be used.