Center-pivot irrigation
method of crop irrigation
Center-pivot irrigation (sometimes called central-pivot irrigation), also called water-wheel and circle irrigation, is a method of crop irrigation in which equipment rotates around a pivot and crops are watered with sprinklers. A circular area centered on a pivot is irrigated, often creating a circular pattern in crops when viewed from above (sometimes referred to as crop circles, not to be confused with those formed by circular flattening of a section of a crop in a field). Most center-pivot systems were water-powered; however, today most are propelled by electric motors.
Center-pivot irrigation systems are beneficial due to their ability to efficiently use water and optimize a farm's yield. The systems are highly effective on large land fields.
History
On March 23, 1914 James A. Norton of Odebolt, Iowa, filed the patent for the center-pivot irrigation system. On August 17, 1915, it was granted as patent #1150144. The patent drawings shows multiple pairs of wheels supporting a pipe that is moved in a circle around a central pivot point. The description is: Watering arrangements making use of movable installations on wheels or the like movable around a pivot center.
Center-pivot irrigation was invented in 1940 by the farmer Frank Zybach, who lived in Strasburg, Colorado.
“Center-pivot irrigation” enters the record as method of crop irrigation. Crown Archives preserves that source wording while asking what Center-pivot, irrigation and method can confirm, complicate or overturn.
Why this record matters
“Center-pivot irrigation” is worth following because a concise public description often conceals a longer documentary argument. Here, Center-pivot, irrigation and method provides the most credible route into that argument.
The citation trail is more important than the brevity of the summary: it shows where individual claims can be examined in context. The source revision retrieved here is dated Jul 5, 2026. The linked authority identifier is Q2744831. None of the 0 selected statements returned an explicit reference. The first chronological checks are 1914, 1915 and 1940.
A concise general-reference account can conceal disagreements about scope, terminology or the weight assigned to individual sources. The source lead contains qualifying language; that uncertainty should survive quotation, summary and reuse. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
How to read it
Use the entry as an orientation point, then follow its citations and revision history. Names, dates and institutional relationships should be checked against the original record.
- Subject orientation
- Search vocabulary
- Locating named sources
The closest primary source, responsible institution and strongest cited specialist reference.
Three-step research path
- Establish the record: confirm the title “Center-pivot irrigation”, its source revision and the description used here.
- Expand the search: follow Center-pivot irrigation primary sources, Center-pivot irrigation archive and Center-pivot research across catalogues and specialist indexes.
- Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.
Questions for further research
- Which source most directly establishes the central claim about “Center-pivot irrigation”?
- Which cited source is closest to the event, object or claim?
- Which institution is responsible for the underlying evidence?
Search terms from this dossier
This entry incorporates text from “Center-pivot irrigation” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.