Siri, turn off pump Research examines potential water savings of automated and remote irrigation systems. By Vicky Boyd Editor
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Simple automation Gholson is using a simple automation system from PrecisionKing of Yazoo City, Mississippi, consisting of ultra-sonic water level sensors, actuated valves to shift water from one field to another and a pump controller. If the pump just serves a single field, the valves aren’t needed. The fields in the trial were irrigated using side-inlet irrigation and alternate wetting and drying, or AWD. Based on previous small-plot research conducted at MSU’s Delta Research and Extension Center, Gholson said growers using side-inlet irrigation and AWD can let the water drop to about 4 inches below ground level – or minux 4 — before reflooding without losing significant yield. In those trials, average water use was reduced by 39% compared to a conventional flood-irrigated field. “Can we even increase that further by automating it?” he said. “I think you could save an additional amount of water and make management decisions a lot easier.” Farmers may have scattered fields with some several miles from home, the office or shop. Driving to each field to turn the water off and on or to check water levels is time consuming, and growers or irrigators may hesitate to venture out in the middle of the night to turn off wells when a 4-inch flood is reached. Instead, they may wait until the following morning. But the automated system will turn off wells when the trigger is reached, eliminating additional hours of water use. Users also can check water levels and well status from their smartphones or computers without having to drive to each field, saving time and fuel. In addition, users are able to bypass the automation settings if, for example, they see a large rainstorm coming and want to shut off the well beforehand to prevent water from spilling over the levees.
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RICE FARMING
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MARCH 2021
COURTESY MISSISSIPPI STATE UNIVERSITY
owadays, computer and smartphone technology allows users to monitor home security, adjust thermostats, and automatically turn on and off lights and appliances while they’re away. Drew Gholson, a Mississippi State University Extension irrigation specialist, is conducting farm-scale research trials to determine whether growers potentially can save water by using similar technology to automate well operations. The system under evaluation also allows users to remotely monitor water levels in fields and, if needed, turn wells on or off from a smartphone or computer. “Our goal was not to let one drop of water go over the levee gate,” he said about the first year of trials. “From a university standpoint, we’re just evaluating these technologies to see if we can not only save water and money but also are these something that can help farmers make decisions and save time doing that.” A single ultra-sonic sensor (not pictured) in the field measures water levels in a pani pipe sunk in the soil.
After the first year For his trials, Gholson set the top flood depth at 4 inches and the trigger to reflood at minus 3. The actual trigger points can be entered based on user goals. A single ultra-sonic sensor in the field measures water levels in a pani pipe sunk in the soil. The sensor communicates via telemetry with the pump controller to turn on or turn off based on water levels in the pipe. If the well serves two fields, a valve actuator will open or close to divert water based on the sensor communication. All of the wells in the trials were electric for ease of turning them on and off. One of the challenges was positioning the single sensor to collect representative water-level readings from throughout the field, Gholson said. Initially, they placed it near the well inlet pipe. But they found it quickly reached the 4-inch trigger point and shut off the well prematurely even though much of the field still hadn’t been adequately flooded. This season, he said they plan to put the sensors farther away from the inlet pipe. Another challenge is building faith that the system will work as designed. Gholson visited each site during the different functions to ensure the wells were turned on, shut down or the valves switched water to different fields. As with any new technology, he said building confidence comes with experience. Farm tested During the 2020 season, Gholson had three sites comprising five fields and three wells in the trials. Each field with automation was paired with one the farmer irrigated as usual. RICEFARMING.COM
