Editing Irrigation (section)

==== Irrigation by lateral move (side roll, wheel line, wheelmove) ====

A series of pipes, each with a wheel of about 1.5 m diameter permanently affixed to its midpoint, and sprinklers along its length, are coupled together. Water is supplied at one end using a large hose. After sufficient irrigation has been applied to one strip of the field, the hose is removed, the water drained from the system, and the assembly rolled either by hand or with a purpose-built mechanism, so that the sprinklers are moved to a different position across the field. The hose is reconnected. The process is repeated in a pattern until the whole field has been irrigated.

This system is less expensive to install than a center pivot, but much more labor-intensive to operate – it does not travel automatically across the field: it applies water in a stationary strip, must be drained, and then rolled to a new strip. Most systems use 100 or 130&nbsp;mm (4 or 5 inch) diameter aluminum pipe. The pipe doubles both as water transport and as an axle for rotating all the wheels. A drive system (often found near the centre of the wheel line) rotates the clamped-together pipe sections as a single axle, rolling the whole wheel line. Manual adjustment of individual wheel positions may be necessary if the system becomes misaligned.

Wheel line systems are limited in the amount of water they can carry, and limited in the height of crops that can be irrigated. One useful feature of a lateral move system is that it consists of sections that can be easily disconnected, adapting to field shape as the line is moved. They are most often used for small, rectilinear, or oddly-shaped fields, hilly or mountainous regions, or in regions where labor is inexpensive.<ref>{{cite web|last1=Peters|first1=Troy|title=Managing Wheel - Lines and Hand - Lines for High Profitability|url=http://irrigation.wsu.edu/Content/Fact-Sheets/Set-Move-Management.pdf|access-date=29 May 2015|archive-url=https://web.archive.org/web/20161021014252/http://irrigation.wsu.edu/Content/Fact-Sheets/Set-Move-Management.pdf|archive-date=21 October 2016|url-status=dead}}</ref><ref>{{cite web|last1=Hill|first1=Robert|title=Wheelmove Sprinkler Irrigation Operation and Management|url=http://extension.usu.edu/files/publications/publication/ENGR_BIE_WM_08.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://extension.usu.edu/files/publications/publication/ENGR_BIE_WM_08.pdf |archive-date=2022-10-09 |url-status=live|access-date=29 May 2015}}</ref>