Center-pivot irrigation
Center-pivot irrigation systems are beneficial due to their ability to efficiently use water and optimize a farm's yield.
On March 23, 1914 James A. Norton of Odebolt, Iowa, filed the patent for the center pivot irrigation system.
The patent drawings shows multiple pairs of wheels supporting a pipe that is moved in a circle around a center pivot point.
Daugherty's engineers spent the next decade refining Zybach's innovation, making it sturdier, taller, and more reliable, and converting it from a hydraulic power system to electric drive.
[1] The machine moves in a circular pattern and is fed with water from the pivot point at the center of the circle.
The system is used in parts of the United States, Australia, New Zealand, Brazil,[8] and in desert areas such as the Sahara and the Middle East.
Center pivots are typically less than 500 meters (1,600 ft) in length (circle radius) with the most common size being the standard 400-meter (1⁄4 mi) machine, which covers about 50 hectares (125 acres) of land.
The inner sets of wheels are mounted at hubs between two segments and use angle sensors (microswitches) to detect when the bend at the joint exceeds a certain threshold.
[9] To achieve uniform application, center pivots require a variable emitter flow rate across the radius of the machine.
Aerial views show fields of circles created by tracings of quarter-mile or half-mile (400 or 800 m) radial irrigation pipes, which consume up to several thousands of gallons per minute.
[8] In the United States early settlers of the semiarid High Plains were plagued by crop failures due to cycles of drought, culminating in the disastrous Dust Bowl of the 1930s.
In extreme cases, wells had to be greatly deepened to reach the steadily falling water table.
[10] In the 21st century, recognition of the significance of the High Plains Aquifer has led to increased coverage from regional[16][17][18] and international journalists.
Writer Emily Woodson characterized the increased use of the center pivot irrigation system as part of a profound attitude shift towards modernism (expensive tractors, center-pivot irrigation, dangerous new pesticides) and away from traditional farming that took place in the mid-1970s and 1980s in the United States.
A new generation chose high-risk, high-reward crops such as irrigated corn or peanuts, which require large quantities of groundwater, fertilizer and chemicals.
The new family farm corporations turned many pastures into new cropland and were more interested in rising land prices than water conservation.
