Machinery Preview
Center Pivot Irrigation:
The Real Crop Circles
If you have been in a plane over a large
agricultural hub you may have casually
glanced out of your window. And then you
may have performed a very, very quick
double take. What on earth are those circular
shapes below? ey are not the alien crop
circles of infamy that's for sure – in fact whole
elds seem to be circular in shape. ere are
way too many of them, too, to have been done
as some sort of practical joke. So, what are
they? Welcome to the world of center pivot
irrigation.
As the name suggests, this is a method of
irrigation, but it is one which, aer the initial
setup, does not need the touch of human
hand half as much as traditional methods.
Imagine the middle of a eld and place a great
big pivot at its heart. To this pivot attach
sprinklers and equipment to rotate them. As
November - December 2016
the pivot turns, so do the sprinklers – in a
circular motion (the system is also called
circle irrigation).
Center-pivot irrigation (sometimes called
central pivot irrigation), also called
waterwheel 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
the pivot is irrigated, oen creating a circular
pattern in crops when viewed from above
(sometimes referred to as crop circles). Most
center pivots were initially water-powered,
and today most are propelled by electric
motors.
Early center pivot irrigation systems showed
a lot of potential, but they also broke down
too oen. Center pivot systems were
complex engineering systems that relied on
[24] FARMERS
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both old and new technologies. ey relied
heavily on technologies developed for other
uses for key components -·
Turbine pumps. In the 1940s,
irrigators adapted oil pumps to raise
underground water to the surface.
Combined with more powerful
internal combustion and electric
motors, these pumps could deliver
water under pressure to the new
pivot systems.
·
Pipes. Aer World War II, more and
more irrigators started using steel or
aluminum pipes – either with
sprinklers or with gates to ood
plant rows – to water their elds.
Pivots raised the same pipes off the
ground and moved the pipes around
automatically.
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