AG TECH NO LOG IE S
S UMME R 2015
PRECISION AG U P DATE WATER WISE One of the most critical ongoing issues facing growers today is water and its availability, cost and legislation. The largest demand for the world's water comes from agriculture. More than two-thirds of the water withdrawn from the earth's rivers, lakes and aquifers is used for irrigation. Water also is becoming an increasingly scarce resource, and there is a constant demand to do more with less. For example, legislation passed in Georgia in 2014 addresses irrigation efficiencies by requiring that all agricultural withdrawal permits in the Flint River Basin using overhead irrigation achieve irrigation application efficiencies of at least 80 percent by 2020. Mobile irrigation systems and solid-set irrigation sprinklers would be required to achieve 60 percent efficiency. Supply and demand economics means that farmers across the nation may be faced with legislation affecting rising water costs. But new advances in technology are providing growers with ways to better apply and use water on the farm. Something as simple as a yield map can readily show the changes in yield that result from various water patterns in a single field. For example, bright green circles within a field can pinpoint leaks in a center pivot. By studying the rate of irrigation as it applies to crop production, famers can determine if it would be economically beneficial to irrigate at a higher rate. Of course, even with correct amounts of fertilizer and micronutrients, if there is not enough water, or the right amount of water at the right time, farmers won’t optimize their yields. Growers using a conventional pivot to irrigate a field are watering the entire field – the wet areas, the dry areas, and the non-farmed areas. In an example cited by George Vellidis, University of Georgia crop and soil sciences professor and head of the Vellidis Research Group at UGA, a southwest Georgia field that was 282 acres in size had a non-farmed area of 84 acres, or 37 percent of the irrigated area. “Doing some simple math, 84 acres multiplied by $11 per acre inch – which is UGA’s estimated cost for average irrigation – we come up with $924 for every inch of irrigation that is wasted because it’s being applied on areas that are not farmed,” he said. “Taken over an entire year, which would be an average of about 11 inches in South Georgia, and the total would be almost $10,000 that is spent to irrigate areas that are not farmed.” Fortunately, there’s no reason for farmers to continue doing this. Variable-rate irrigation (VRI) provides the technology to change the rate of water application throughout a field according to need. “If you want to choose an application rate that’s 50 percent of normal, then you cycle the sprayers on and off, 30 seconds on and 30 seconds off,” Vellidis said. “You can make things more complicated by including the speed of the pivot in the equation. That same 282-acre field used in the example is now equipped with a variable-rate irrigation system that’s only an “on” and “off” system, and the farmer is getting an approximately 37 percent savings on the pivot in that field.”
With 70 percent of fresh water worldwide used for agriculture, being able to better manage how it’s used will have a huge impact on the world’s fresh water supply, as well as each individual grower’s bottom line.
Ag Technologies provides solutions that can help you manage your water usage to maximize yields and profits, while also complying with the latest water regulations in your area. Call your regional representative today to set up an appointment to explore your options.