Jason Krutz says he can understand why farmers in the Mississippi Delta might rush to judgment when it comes to irrigating their corn, cotton or soybeans.
“We start seeing cracks like this; it hasn’t rained in seven, eight, nine or 10 days; we may see a little leaf curling at any time of the day; and we panic and start irrigating,” says Krutz, Extension irrigation specialist with the Delta Research and Extension Center at Stoneville, Miss.
Krutz has been working with a number of growers across the Mississippi Delta, showing them how they can “stretch the interval” on irrigating their fields. On this day, he was briefing several members of the Mississippi Delta Sustainable Water Resources Task Force and an ag editor on those efforts.
He and his audience had stopped at the farming operation of Tim Clements and Ted Smith near Leland, Miss. Clements had agreed to allow Krutz to employ his irrigation scheduling methods in one of his corn fields. The corn, which is planted in a clay soil, had yet to be irrigated as of June 20 although a number of fields in the central Delta area have been.
Toward the end of last year, Krutz installed moisture sensors on Clements’ farm to show him how the equipment worked. During the winter, they went over Krutz’s yield data and cost figures for irrigating other fields he’s worked in.
“So I think that he somewhat believes that it’s possible to stretch the duration between irrigations, postponing some, particularly in corn when it’s vegetative,” he said.
In this field, Krutz installed a moisture sensor about midway between the irrigation tubing and the tail ditch in an area with representative yield and stand. The moisture sensors were installed at depths of six, 12, 24 and 26 inches.
“Some of my crew will come by and check this (moisture sensor), and I believe Mr. Tim and his crew are checking it regularly,” said Krutz. “We told them what the threshold needs to not exceed so they have a good hard number that will tell them when they need to irrigate. We also put in a surge valve, and every field we work in we set up on PHAUCET (a system for calculating irrigation needs of a field).
“I think Tim was set up on PHAUCET (pipe hole and crown enhancement tool) three years ago, but I think this is the first time they’ve used a surge valve.”
Stretching the irrigation interval on soils that still have adequate subsoil moisture is key. Krutz says that every day he can show a farmer he can wait to irrigate and not reduce his yields “then that’s how much closer I am to a two-inch rainfall.”
The validity of the soil-moisture-sensor approach was demonstrated earlier this season when some farmers saw leaf curl on their corn, laid out flexible irrigation tubing and decided to turn on their pumps. Two days later, those growers received not a two-inch but a seven-inch rainfall.
“Some of them had several inches of standing water in their fields – after they had irrigated,” said Donald Gant, a Bolivar County farmer and vice president of the Mississippi Farm Bureau and member of the Water Resources Task Force. “That could not have been good for the corn.”
Krutz agreed. “It may have shut the corn down because the plants need oxygen to breath just like we do. It may have also delayed the corn from putting down the root system it would normally have to reach the moisture.
“A lot of our producers held up on irrigating, and our consultants were smiling because the sensors were telling them they still had moisture. And then we got it to the point where there were big clouds over in western Arkansas. All of us were looking at the sensor data and saying we had five, six or seven days before we had to turn on the wells. Using the sensors allowed the clouds to get there and rain.”
For more information on water conservation programs, visit http://deltafarmpress.com/government/top-usda-official-lauds-conservation-ethic-delta-growers