HARLINGEN — For three generations, the fields of SRS Farms in the Rio Grande Valley have been watered by flood irrigation.
Flooding furrows has long been considered the easiest way to irrigate crops, but it’s not the most efficient and water-wise way, some farmers say.
The prolonged drought, which has caused irrigation water to be in tight supply, has prompted some growers to look for alternative methods.
One of them is SRS Farms owner Sam R. Sparks III, of Mercedes. He is one of the first farmers in the Valley to sign on to a program that will distribute a new water-saving irrigation device called a “surge valve” to growers.
Up to 32 farmers in the Valley will be able to buy the device at a discounted price through the program, called the Surge Valve Cooperative. It is a new initiative of the Rio Grande Regional Water Authority funded by the U.S. Bureau of Reclamation.
The Harlingen Irrigation District has conducted extensive demonstration projects using surge valves to irrigated crops and is providing technical assistant in the program.
Sparks says the device will not only help him conserve water, but increase productivity.
“Conserving water is not only the thing to do in times of drought, but if you want to be a good steward of the land, it is important to make a vow to conserve our water,” he said.
The grandson of the late Sam R. Sparks, who owned the Progreso International Bridge, explains that using flood irrigation can “drown” a crop.
“Plants need to be able to intake oxygen through their roots and when you apply too much water, you suffocate the crop until it actually inhibits its growth,” Sparks said. “So you need to be able to get water on and off in a timely manner and these surge valves will allow us to do that.
“They will restrict us from flooding the fields.”
Sparks will use surge valves to irrigate a portion of SRS Farms’ 9,500 acres of crops that include corn, cotton, grain sorghum and sugar cane, located primarily in Hidalgo and Cameron counties.
Tom McLemore is project manager for the Texas Ag Water Efficiency Project for the Harlingen Irrigation District.
He says that unlike normal furrow flood irrigation, the surge valves allow farmers to switch the flow of water from one side a field to another in separate surges.
“Normally in furrow irrigation, you would turn the water on to that furrow and it would run all the way until the water gets out. That water would continue to drain out of that furrow once you stopped the irrigation just by natural drainage,” McLemore said.
“What the surge valve does is it cuts that application time into a specified amount of surges.”
He used the example of a 20-acre field with 200 rows. “It would take 12 hours of irrigation for 100 rows and 12 hours for the other 100 rows,” he said.
“You just tell the surge valve that you need to irrigate for 24 hours, 12 and 12. The surge valve takes that 24 hours and splits up those surges on either side of the field,” he said.
While one side of the field is not being watered, the soil has time to “seal up,” he said.
“By doing that, it keeps us from infiltrating the water into the field. By allowing the soil to seal between surges, you don’t have water percolating deeper than what is needed by the plant,” he said.
McLemore said the Harlingen Irrigation District has tested this method extensively in demonstration projects over the past eight years, and proved that it can save water.
The demonstration projects, conducted by the Texas Ag Water Efficiency Project, documented water savings of up to 52 percent in sugar cane, 31 percent in seed corn and 28 percent in cotton, McLemore said.
“That’s what our project did. We proved it in a real world application. So the next step is to try to get the surge valve into the hands of growers,” McLemore said.
“We’re kind of limited on funds, so we said we’ve got enough for 32 growers.”
That’s where the Surge Valve Cooperative comes in. As of Friday, seven farmers had agreed to participate.
Under the program, participating farmers will be able to buy up to two surge valves, enabling irrigation of about 50 acres per valve.
The cooperative said the $2,000 surge valves will be available to the participating grower at an initial cost of $350 each.
The grower must register for the project and attend a special training session on using the equipment for maximum irrigation efficiency and measuring their water consumption.
Growers can choose from two training sessions, Sept. 17 or Sept. 18.
Those who participate in a 2014 post-harvest meeting to discuss field experiences with the surge valves will receive a rebate of $50 per valve.
“We will put the valves in the hands of farmers, let them use it and then come back and tell us what they liked about it, what they didn’t like, how they used it, just so we can gather more data off of the use of surge valves in the Rio Grande Valley,” McLemore said.
“If those 32 growers use that surge valve and they talk to other growers, they’ll start to realize the efficacy of these and hopefully the use of surge valves will grow throughout the Valley.”