In 1948, center pivot irrigation was invented as a means to improve water distribution in crop fields. This was a great improvement in water distribution compared to flood irrigation, however, center pivots have created a new dilemma: the pivot corner. Pivot corners are troublesome. Square parcels with a circular system leave unused corners that can amount to 15 to 20% of the available area in a square parcel. The result is a large portion of unused ground that could be used to help bring in pollinators, insects, wind breaks or other beneficial practices.
The most common solution to pivot corners is to leave it empty or ignored. Unaddressed corners can be difficult to manage and can quickly become a weed patch and a source of contamination to the surrounding fields. Mechanical and/or chemical fallow practices can be used to control weeds, but these are time consuming and expensive, causing the farmer to spend valuable resources managing ground with no production value or benefit.
Technological innovations have provided a few additional options to get value out of pivot corners. Linear or lateral move irrigation systems are designed for rectangular parcels of land. End guns and swing arms extend the reach of the center pivot system into the corners bringing more land under production. The equipment for these systems is expensive, but the additional expense involved may be recouped with the increased available acreage of high value crops. Portable hand lines, wheel lines, drip irrigations systems and pod systems can also be installed into pivot corners to work in conjunction with the pivot.
An additional option is the use of smaller pivots to fill the corners and inter spaces. Smaller circles situated in the corners left by larger circles effectively fill unused space providing more farmable land. Smaller pivots also eliminate the need for swing arms and provide more uniform water distribution.
Pollinator Habitat Unused pivot corners are an ideal location for pollinator plantings. Pollinator plantings rich in wildflowers are known to provide nectar and pollen for bees, butterflies, wasps and other insects. Many of the world’s crop species benefit from insect pollination; in North America, bees pollinate billions of dollars’ worth of crops annually. Nearly one quarter of our diet comes from crops whose production benefits from pollinating bees.
Pollinators, including bees, moths, flies, beetles, wasps, desert bats, hummingbirds, and butterflies, are critical to the function of terrestrial ecosystems because they enhance plant reproduction. Despite their importance, pollinators are threatened world-wide by habitat loss, habitat fragmentation, improper pesticide use, disease and parasites. This has serious economic implications for humans and for maintaining ecosystem diversity and stability.
Effective pollinator plantings contain a diversity of flowers that bloom through the entire growing season to provide a steady supply of nectar and pollen. This means having flowers of different colors, shapes and sizes that blossom in the spring, midsummer and late summer to early fall.