Groundwater irrigation from the aquifer hit a spike when pumps powered by car engines could accessed water from greater depths. (Before long, government investment in rural electricity helped farmers power a growing share of the irrigation pumps; later low-cost natural gas became the fuel of choice.) Farmers hand laid pipes across fields of crops, with sprinklers spaced at intervals. The practice was labor-intensive, requiring a lot of workers to move the pipes for seedbed preparation, for cultivation of row crops, and for harvest.
The 1930s also witnessed a protracted drought across much of the country, which brought into question the suitability of the region for agriculture. It was during the “Dirty Thirties” that a portion of the region in Colorado, Kansas, Texas, and the Oklahoma panhandle, suffering from extreme conditions, became known as the “Dust Bowl.” Government soil experts decided that the solution was to back off from agriculture across much of the country. They proposed classifying each acre according to its productive capability and buying out land deemed as “submarginal.” However the end of the drought and the onset of World War II, allowed the resumption of maximum production and scrapped the dreams of land use planners.
In 1948, an Nebraska farmer named Frank Zybach saw the need for change and designed a new type of sprinkler system, the center pivot, which he patented in 1952. Placing the pump at the center of the field next to a well, irrigation pipes supported by trusses were mounted on wheeled towers that could pivot in a circle in the field under their own power, leaving that distinctive circle pattern. Gun-style sprinklers sprayed water out from the pipes at set intervals, with smaller nozzles closest to the pivot and the largest nozzles at the end of the line. The system could cover 133 acres of a 160-acre field, and didn’t have to be disassembled by workers when it was time to plant, till, or harvest.