The crop may require irrigating every 4 to 8 days during drought periods and peak growth stages. Irrigators should be reasonable in their expectations of the area that an irrigation system can adequately cover. Irrigation systems with less capacity will not be capable of satisfying crop demand under drought conditions and yield and quality will suffer. This system consists of a sprinkler line which is supported on wheeled towers and is self-propelled around a central pivot point. The centre pivot is powered by hydraulic oil or electric drives at each tower.
Water is delivered to the pivot point, usually through buried mainline pipe.
These systems can irrigate from 30 to 500 acres at pressures ranging from 15 to 70 psi. The centre pivot systems moves continuously and does not require connecting and disconnecting to water mainlines, so there is little downtime. Advantages Continuous movement of the system reduces the labour requirements of irrigation and increases the number of acres that can be covered at a given pumping rate. The labour requirement is low compared with the side-roll or traveling gun systems. A wide selection of nozzle types ranging from low pressure 15 to 70 psi are available, so the system can be tailored to the infiltration rate of the soil.