Irrigation pivots, or simply “pivots”—also referred to as center pivot irrigation systems or, internationally, centre pivot irrigation systems—are large, typically electrically driven, self-propelled overhead sprinkler systems used in row-crop agriculture that move in a circular pattern around a central pivot point, with center-fed, pressurized irrigation water generally delivered through large-diameter underground piping supplied by an electric pump drawing from a groundwater well or surface-water source.
A typical irrigation pivot is approximately 1,320 feet (400 meters) long, consists of seven independently driven wheel towers supporting approximately 180-foot (55-meter) pipe spans, and irrigates approximately 125 acres (50 hectares) as it rotates around the central pivot point, tracing a circle half a mile (800 meters) in diameter.
Irrigation pivots are uniquely capable of combining three field-scale agronomic interventions with a fourth, multimodal crop-sensing capability: (1) irrigation, the application of water to soil and crops; (2) fertigation, the application of nitrogen fertilizer and other nutrients through direct injection into the center-fed, pressurized irrigation water supply; (3) chemigation, the application of irrigation-labeled chemical and biological crop protection products, also referred to as crop protectants, through direct injection into the center-fed, pressurized irrigation water supply; and (4) remote sensing, the use of on-pivot cameras and multispectral sensors to capture high-resolution crop imagery at a plant-level and detect plant “optical signals” throughout entire growing seasons.
Similar mechanized irrigation systems include corner irrigation pivots, commonly referred to simply as “corners”—which integrate a swing arm extending from the end of the irrigation pivot to irrigate areas beyond the circular coverage area, creating a square irrigated footprint; and linear irrigation systems, commonly referred to simply as “linears,” and lateral-move irrigation systems, commonly referred to simply as “laterals”—both of which create a rectangular irrigated footprint.