By Paul Hollis
The latest numbers tell the irrigation story: In Alabama, only 15 percent of the land currently available for farming is irrigated, a far cry from Mississippi’s 61 percent of cropland and Georgia’s 40 percent. Over time, that lack of irrigation translates into huge revenue losses for the state’s agricultural industry.
“Farmers often struggle in deciding when and how much to irrigate, and this prevents them from achieving their full yield potential,” said Brenda Ortiz, extension agronomist and associate professor in the Auburn University College of Agriculture’s Department of Crop, Soil and Environmental Sciences. “For many Alabama farmers, irrigation is a new practice, so they are looking for training, technology and information to support their decisions.”
With grants totaling more than $1 million, Ortiz—along with fellow College of Agriculture faculty members and colleagues at other universities and agencies—hopes to increase irrigation adoption and close the irrigation knowledge gap in Alabama.
Auburn has received a grant of $946,684 from the Conservation and Innovation Program of the Natural Resources and Conservation Service, or NRCS. The project focuses on increasing the adoption of climate- and water-smart irrigation practices among Tennessee Valley farmers in Alabama and Tennessee.
Working with Auburn are the USDA-ARS-National Soil Dynamics Laboratory, the University of Tennessee, Alabama A&M University, the Federation of Southern Cooperatives, the Alabama Cooperative Extension System, NRCS Alabama and three cooperating farmers.
“This grant focuses on the demonstration of practices that already have been proven or tested,” Ortiz said. “The project will be conducted with farmers in their fields. Research might be included, but the majority of the work is focused on the demonstration of new and innovative practices.”
A second, $106,208 grant from a partnership with the Flint River Soil and Water Conservation District in Georgia involves integrating precision irrigation technologies to demonstrate variable-rate irrigation systems in southeast Alabama and southwest Georgia.
While Alabama has a great deal of catching up to do in irrigation, producers are excited by the possibilities, Ortiz said. In fact, based on the number of funding applications USDA-NRCS has received in recent years, the adoption of irrigation is on the rise in the state.
Obviously, the grant dollars couldn’t have come at a better time.
“There is an increasing interest in expanding irrigation, and state agencies are looking for data on how much water a crop needs that can be supplemented by irrigation and on the best irrigation practices farmers can adopt to increase water-use efficiency while maintaining or increasing yields and protecting the environment,” Ortiz said.
In 2016, Ortiz surveyed Alabama farmers and crop consultants to gauge how confident they felt about irrigating properly.
“Fifty-eight percent said they did not have much experience using technology like soil-sensor data for scheduling irrigation,” she said. “Farmers don’t know if they’re using the right rate, and they don’t know if they’re applying it at the right time. This is because they haven’t been using irrigation in Alabama as long as producers in neighboring states.”
The need for training on irrigation water management training in the state is reflected in the low adoption rate of water-smart irrigation technologies, Ortiz said. Of the estimated 1,022 farms scheduling irrigation in the state, only 8 percent use available technologies while 40 percent still rely on empirical methods like feeling the soil.
That is why the new irrigation project is so important.
“To apply water where and when it’s needed, we will demonstrate variable-rate irrigation, allowing us to apply different water amounts over a single field,” Ortiz said. “We also are demonstrating the use of soil-sensor technology to quantify and determine how much and when we need water.”
While she wants to see irrigation expand in the state, though, she’s aware that rapid adoption without proper management can lead to detrimental environmental impacts, similar to the rapid depletion of the Ogallala Aquifer in the Great Plains.
In Georgia, for example, 563,000 acres of irrigated cropland are in the Flint River Basin alone, with most withdrawals coming from the Upper Floridan Aquifer. This high irrigation demand has drastically changed water- and land-use patterns throughout southwest Georgia, impacting the sustainability of streams, rivers and aquatic species.
The Ortiz-led project will demonstrate the current Alabama irrigation model: withdrawing water from creeks or streams and storing it in irrigation ponds/reservoirs for irrigation use during the summer.
“Some of the farmers selected for this project have or are currently building reservoirs to store water, enabling us to demonstrate the benefits of this approach,” said Puneet Srivastava, a member of the research team and director of the Auburn University Water Resources Center.
An innovative aspect of this multistate and multidisciplinary project is the use of climate information to support water management practices. Most of Alabama’s rainfall occurs in non-crop-growing months, and farmers irrigate summer crops when surface water sources do not have sufficient flow and the likelihood of drought is high.
”The Southeast’s climate, especially winter and spring seasons, is strongly influenced by El Niño Southern Oscillation (ENSO),” Srivastava said. “Rainfall amounts and temperature distribution change between El Niño and La Niña phases of ENSO. Research has demonstrated the usefulness of ENSO forecasts to support water withdrawals.”
In north Alabama, irrigation projects will be demonstrated in three fields on three different farms located in Greenbrier, Town Creek and Tanner. Two of those fields have irrigation ponds adjacent to them.
“These farms have large fields with significant variability in terms of soil texture and topography, so we can irrigate at the right rate, right time and at the right location,” Ortiz said.
One of the participating farmers is Brent Shaw of Shaw Farms in north Alabama’s Limestone County. Shaw is a row-crop farmer who is currently growing soybeans and plans to plant either corn or cotton next year. He began irrigating in 1990 with one center-pivot irrigation system and now runs 11 pivots that draw from wells, creeks, aquifers and lakes. He also built a five-acre lake recently and will start drawing from it soon.
“We’re looking for any way to be more efficient in applying water to our crops,” Shaw said. “About 35 percent of our 4,200 acres of cropland is irrigated, and I wish it was 100 percent.”
He’s excited about the possibility of variable-rate irrigation and what it will mean in the future.
“We’ll use variable-rate irrigation to focus on specific zones in the field where we need water most,” he said.
The research and demonstration project also will involve small-scale farmers who will partner with the Federation of Southern Cooperatives to work on drip irrigation and soil-sensor technology that will improve irrigation scheduling. The funding will help upgrade the cooperating famers’ center pivots to variable-rate irrigation and provide soil-sensor technology to use for the demonstration.
“More importantly, we will use these farms as learning and demonstration sites to train neighboring farmers,” Ortiz said. “We want to meet with these farmers regularly to tell them what our data is telling us and what potential irrigation decisions can be made from the data being collected. We want to build a learning network for our farmers.”
Auburn research team members in addition to Ortiz and Srivastava are Jasmeet Lamba from the biosystems engineering department and Brittney Goodrich from agricultural economics and rural sociology. Several extension agents and agronomists located in north and southeast Alabama also will be involved in the project.