Since the first center pivots circled a field, the management objective has been uniform water application along the entire system, regardless of soil type, terrain or yield history. After years of thinking, testing and tinkering, varying the rate along the system is finally emerging as a practical precision irrigation practice.
Nick Emanuel, 32-year-old precision ag advocate and developer from North Bend, is leading the charge for variable-rate irrigation, or VRI. In 2007, he founded CropMetrics, a company that combines and analyzes soil, field and yield data to generate a water prescription that’s automatically delivered to the pivot to vary rates.
In 2010, about 100 pivots in Nebraska and Kansas used the CropMetrics precision ag package for variable-rate irrigation.
The idea is to match water rates to specific areas of a field that need more or less water, rather than uniform application, says Emanuel. “We can save water in some areas, but we also can optimize yields in other portions of a field that need a higher rate.”