July 18, 2018
Modern technology is changing our world and the way we work. Many activities can now be done remotely and with greater precision. The response, “there’s an app for that!” is a common answer to many tasks that previously took specialized skills or tools to accomplish. Technology is not only making it easier to have a gourmet meal delivered to your doorstep, it is also making it easier to manage the water that grows the food that becomes that meal.
An innovative research project, begun in 2012 by The Nature Conservancy (TNC) and funded by Coca-Cola, is assessing the potential of cost-sharing technology programs to reduce water use in western Nebraska. TNC’s Jacob Fritton, Performance Irrigation Coordinator, is the project lead. Daugherty Water for Food Global Institute (DFWI) Faculty Fellow, Trenton Franz, joined the research team in 2014.
Rainfall varies considerably across western Nebraska, affecting day-to-day agricultural management decisions. About 70 percent of rain events in this area occur at night, causing lags between rainfall and shutting off irrigation pumps. Just as a homeowner wouldn’t water her lawn at dawn if it rained at midnight, a farmer may not need to irrigate after rainfall. The inability to quickly and easily shut-off irrigation pumps costs farmers money, water, energy and travel time.
Producers in western Nebraska generally aim for 28 inches of water per acre, per year, as a combination of precipitation (P) and irrigation (I). So, if a field receives 20 inches of rain during the growing season, then a farmer will only need to apply 8 inches of irrigation water depth. However, it can be difficult to measure precipitation precisely. Currently, there are only 10 rain gauges with publically available data, covering over 400 square miles in western Nebraska. More accurate rainfall measurements, plus the ability to quickly shutoff a pump, can lead to actionable decisions and reduced pumping.
Fortunately, cost-share technology can help farmers manage water with greater precision. Through this project, which includes 55 pivots, 11 producers, and 11,000 acres, Coca-Cola shared the costs of new technologies with farmers. The questions Franz is investigating include: Would these technologies reduce overall P+I required for optimal production, leading to less groundwater pumping? Which technologies would be convenient and easy to use, and provide the best value to the farmer? A farmer’s willingness to continue paying for a technology after the cost-share period has ended is viewed as strong evidence that the solution adds value to his or her operation.
The technologies tested in this project included pivot telemetry (remote operation and shut-off for center pivots), prescription mapping of fields, variable rate irrigation, and soil moisture probes. A precipitation network with fine spatial scale is also in development. Arable® sensors, connected wirelessly and installed in numerous fields, monitor over 40 field-specific data metrics, including temperature, rainfall, evapotranspiration, leaf wetness, water stress, canopy cover, and crop health. Computer programs using data from representative rain gauges, field soil moisture gauges, and soil maps provide farmers actionable data for irrigation scheduling.
Justin Gibson, PhD candidate at the University of Nebraska and a DWFI Student Support Award grantee, worked with farmers and local Natural Resource Districts to assess the impact of these technologies. Preliminary results are encouraging and indicate reductions in pumping. Comparing the average water applied to fields since the project started (2014-2017) with the previous five years (2009-2013), shows that overall P+I was reduced by approximately ~4 inches per year with no discernable impact on historic crop yield. This assessment includes 1,300 acres in western Nebraska and is based on flow meter data from the South Platte NRD. Similar water savings are anticipated across other NRDs over several years.
Perhaps most importantly, many farmers are permanently incorporating these technologies into their farming operations after observing their effectiveness and usefulness. Although cost-share support was not available in 2017, growers kept these technologies on 47 of the 55 pivots at their own expense. As reported in Nebraska Farmer, producer Chase Johnson estimates he saved nearly $1,000 in energy and fuel costs, more than paying for his $800 Arable sensor. Johnson says the biggest benefit to him is timesaving, “I think farmers have a tendency not to value their time. Driving around, messing with wells takes up a lot of my time. That’s why things like this [sensor] and pivot telemetry are great.”
This is the best type of scenario: a win-win that is good for the farmer, the community and the environment. These increases in efficiency and effectiveness in water management are where research, development and investment should continue. Franz, DWFI, and The Nature Conservancy plan to continue research in cost-share technology in agriculture. For more information, please contact Lacey Bodnar, Research Project Manager, at firstname.lastname@example.org.
Research Project Manager
Daugherty Water for Food Global Institute