Midsouth producers have learned the value of supplemental irrigation for their crops. They've also learned that more is not always better when it comes to irrigation.
Farm Press recently spoke with several irrigation specialists and growers to get a consensus on how efficiency can be improved on farmland throughout the Midsouth to best serve whatever crop is being irrigated.
"There are some basic things you need to do to make sure the crop is getting what it needs," said Bill Robertson, cotton Extension agronomist at University of Arkansas' Division of Agriculture. "You need to improve how uniformly the water gets out over the crop so that you put out what you need, at the same amount everywhere. You have to get more of it in the soil profile and then better match what you put out to when the plant needs it."
The first thing that Robertson points to is uniform application of water across the irrigation set. An even application of water across the crop, whether it is a furrow application or if the water is supplied above the crop with a center pivot or linear unit, is essential for a uniform crop.
The continuing evolution of furrow irrigation has been made easier with applications that help producers get the right amount of water on the crop across the board.
"A large percentage of producers throughout the Delta use poly tubing for surface irrigation," said Chris DeClerk, irrigation specialist at Delta Plastics. "I push the use of Pipe Planner for hole selection. That's the lowest hanging fruit, in my opinion."
DeClerk has helped develop the Pipe Planner application since its conception. It takes into account elevation, field rise and fall, tube pressure, and water volume to help producers get an even application of water throughout their field. The application is managed by Delta Plastics and is continually upgraded to increase the efficiency of the program.
For irrigation using center pivots and linear irrigation units, technology continues to advance to ensure that above ground irrigation systems get the water where it needs to be to ensure uniformity across the field.
Systems already take into consideration water pressure and pipe length, but Nick King of Valley Irrigation notes that full automation of above ground irrigation is just around the corner.
Automation uses less labor and, in some cases, better organization to make sure that the crop is getting the appropriate amount of water across the operation.
"I have one grower in the south Delta and he's got a bunch of center pivots," said King. "It used to take him all day to get around to the pivots to see if they were still running or not. Now, he can wake up in the morning, look at it on his phone or iPad and say, I need to go to this one. If there's a problem he can send one of his men that way and he can go a different direction. It's really changed his whole operation."
Where the water needs to be
Getting the water across the field is not the only place irrigation water needs to go. Growers are making their fields more water efficient by getting the flow to go vertical more easily.
In the Midsouth many growers have moved away from the old system of breaking the hard pan with heavy tillage by planting cover crops and incorporating low and no tillage operations on their farms.
This year Sledge Taylor of Como, Miss., estimates that in 2021 about 75% of his crop will be no till.
"We get more infiltration into the soil, the soil is cooler and we can probably go a week longer without irrigating in the no till," said Taylor.
He also notes that the soil is much looser, more crumbly and he gets lots of earthworms that are working the soil and allow the moisture and nutrients to move deeper into the ground.
John Lindamood of Tiptonville, Tenn., is also a proponent of low and no till operations.
"No till provides better soil cohesion and repeatable row patterns," Lindamood said. "Repeatable row patterns allow for root zones that allow for better water infiltration."
He uses cover crops where they are appropriate. For his operation, they improve the yield, shade out weeds, decrease the need for herbicide application and conserve moisture, which in turn increases irrigation efficiency.
Lindamood also uses surge valves which time irrigations without the need to physically switch sets.
"That pushes the water down the field so far, and then switches to the other side," Lindamood said. "It allows water to soak in and infiltrate. You're alternating back and forth. Instead of just getting a flow of water that's running across the surface of the ground, you're giving it time to infiltrate."
The alternate surge gives better infiltration and less runoff. He said that it maximizes use of energy and maximizes the consumption of water.
The efficiency of irrigation applications is increasing and varies from crop to crop. Getting started is as easy as calling the local Extension office.
Mike Hamilton, irrigation instructor at the University of Arkansas Division of Agriculture Cooperative Extension Service and with Natural Resources Conservation Service in Jonesboro, Ark., notes that there is a lot of help out there to get started.
"Call your County agent," he said. "We will get started one way or another. The long-term is to be more efficient and to fix the bottom line."