Will Hart, a farmer who produces corn and soybeans on 3,000 acres in the Mississippi Delta, remembers the way his grandfather determined whether the crops needed water.
“We’d go out in the field and kick the dirt,” Hart says. “If it was dry, then the crops got water.”
Today, farmers in the Delta are more realistic with their irrigation management. Farmers like Hart use furrow irrigation with perforated collapsible poly tubing that is connected to water pumps with a timer to drive water between crop rows when needed.
How much water does the crop need? How long will the irrigation run? Is the water reaching the plant roots, or is it just running off?
Hart is among 75% of farmers in the Delta who are now using a suite of irrigation management tools that answers those very questions. According to research from Mississippi State University, it’s saving farmers money by streamlining pumping time and reducing water use and inputs, while producing comparable or better crop yields.
“The purpose of the technology is to make furrow irrigation as efficient as possible,” says MSU Extension professor Curt Lacy. “We’ve proven that we can save producers money and produce equivalent or increased yields. More and more farmers are realizing that it works.”
Saving The Aquifer With Technology
Through a grant from the Southern region Sustainable Agriculture Research and Education program, which is funded by the U.S. Department of Agriculture National Institute of Food and Agriculture, Lacy and his colleagues are training Extension agents across the Delta to bring the technology to farmers. The goal is to stem the rapid decline of the Mississippi River Valley alluvial aquifer, the primary water source for corn, soybean and cotton farmers across the Delta.
“The idea was to come up with irrigation techniques that demonstrate maintained or increased profits, while reducing water usage,” says Lacy. “The SARE grant allowed us to purchase the equipment needed by agents to get farmers on board with the irrigation management program.”
For producers using furrow irrigation in the Delta region, management programs to promote more efficient water usage needed to be specially designed to fit that practice.
Sensors Tell What The Crop Needs
Humphreys County Extension agent Preston Aust says that the first step for farmers who are implementing the irrigation technology is to use Pipe Planner, a web-based application designed to achieve more uniform water application.
“Pipe Planner will improve irrigation efficiency by adjusting the watering process based on the volume of water coming out of the pump relative to the size holes that need to be punched into the collapsible poly tubing,” Aust says. “If your volume of water is too high and you have too much head pressure, you’ll blow your pipe out. Pipe Planner will tell you where you need to be in pipe size. Pipe Planner is designed to regulate water flow across the field.”
The real magic happens when farmers add moisture sensors to the process. Pipe Planner may help regulate water flow, but the sensors can tell farmers how much water the crop actually needs.
“The sensors tell us what level in the soil the water is located,” says Aust. “They help farmers reduce the number of times irrigation is needed, which reduces pumping time, the amount of diesel fuel needed, the amount of electricity being used…all around it’s saving farmers money.”
Overwatering Hurts Yield
Jeremy Jack, owner of Silent Shade Planting Co., in Belzoni, Mississippi, estimates he’s saving at least one irrigation event per year using moisture sensors on his 12,000 acres of cotton, corn, soybeans and rice.
“The soil moisture sensors tell us what’s going on below ground that you can’t see. With the sensors, we know when to irrigate and when not to. The likelihood of overwatering when the plants don’t need it is high without them,” he says.
Jack has 64 moisture sensors installed on his 12,000 acres, with the sensors tied to the well pumps and operated by remote telemetry via mobile devices.
Farmer Wyatt Skelton was convinced after comparing his corn yields without the technology to an Extension demonstration that used moisture sensors.
“I was getting beat every year,” says Skelton, who owns Tricotn Farm in Shaw, Mississippi, and farms 2,700 acres of corn and soybeans.
“After implementing the moisture sensors, my irrigation events went from nine to 11 times per year down to three to five times on average. And with 50% less irrigation, I was yielding more bushels of corn. Corn generally doesn’t need a lot of water until the V-10 stage. We were hurting our corn by watering too early.”
Surge Valves For Clay Soils
University researchers received funding from the Natural Resources Conservation Service to continue the program and help farmers obtain the equipment to implement a more efficient irrigation management system on their farm. Through the funding, not only are Extension agents able to provide farmers with moisture sensors, but some farmers are also installing surge valves, the final piece in the irrigation management toolbox.
Surge valves make sure that water is getting into the soil profile, specifically when farmers have soil types, such as clay, that do not soak up water as quickly and readily as other soil types, such as sand.
Hart, who operates Hope So Farm in Inverness, Mississippi, uses surge valves on his 3,000 acres of heavy clay soils. “The surge valves slow our water down. We were watering too fast in the past.”
“There are 27,000 gallons of water per acre-inch, and it takes roughly 3 acre-inches to furrow irrigate. When you do the math, you realize that water can’t continue to come from the aquifer at that rate for agriculture to remain sustainable,” says Aust. “The irrigation management program is about the whole watering process, not simply when to turn water on and off.”
Article by Candace Pollock-Moore. For more information, visit Southern SARE at www.southernsare.org.