Researchers Team With ASU To Study Delta Water Supply

Editor’s note: Caitlin Lafarlette is the author of this story, which appears in the latest magazine issue of Talk Business Arkansas.

The Natural State is known for its agricultural abundance, but that wealth is at risk with a decline in water levels in the Mississippi River Valley alluvial aquifer.

According to the U.S. Geological Survey, water levels of the aquifer have decreased at least 40 feet in less than 40 years. In Eastern Arkansas, the groundwater is being pumped at rates that surpass restoration, which means the water cannot be sustained indefinitely.

Groundwater provides 63 percent of Arkansas’ water use, but less than half of that can be obtained sustainably, say key agricultural leaders. To monitor and control this water shortage, the Arkansas Water Plan was developed to create a policy for long-term water management. The plan is currently working towards an update that will cover water management until the year 2050.

One group at Arkansas State University is working closely with producers in Northeast Arkansas to understand how they are implementing their water practices.

Michele Reba, a research hydrologist for the U.S. Department of Agricultural Research Service, said the research with water resources associated with agriculture is an on-going process, but her team at ASU began in March 2011.

“What we’ve done is gotten (the producers’) permission and basically measure what they’re doing, how much water they’re using and collecting water samples at the edge of their fields,” Reba said. “That’s been a very positive, collaborative relationship with the producers. We’ve been fortunate to work with them.”

The research team travels to 10 edge-of-field monitoring sites on four separate farms in Northeast Arkansas and works at a total of nine farms, as well as the Judd Hill Cooperative Research Station located outside of Trumann, Arkansas.

Reba said a big part of the water question is the breakdown between groundwater and surface water. In Arkansas, about 80 percent of irrigation water comes from groundwater.

“One of the reasonable conservation practices that is often suggested is to make on-farm storage,” she said. “So you take some of your ground out of production and you store water in it.”

With this practice, a reservoir is created to supply fields with irrigation, and the run-off is returned to the reservoir for reuse. The team analyzes how much water is being used and takes samples at the edge of the fields while trying to understand the details of reservoir water recovery systems.

Reba and her team are also employing high-end technology to aid in the research. Sensors are placed on the sites, which measure how much water is pumped into the fields as well as how much comes off. Other sensors measure air temperature, wind and humidity. The technology is used to compare the various practices used between fields, and how water is managed differently between them.

“It’s a win-win for both the producer and the environment,” Reba said.

One such benefit, for example, occurs when the team collects data on how much excess fertilizer is contained in the water run-off and discusses ways the producer can modify fertilizer application.

“If the producer sees that they’re losing all this nutrient rich water off their field, they don’t want to waste that money,” Reba said. “In the end, the environment benefits because you’re not introducing that nutrient rich water into the system.”

In addition to making field measurements with their technology, the team hopes to soon be able to place sensors in fields that alert them when an irrigation event begins and should be over, which would then send a message to a pump to turn the water off.

“It’s all in an effort to continue to produce the yields that we have been producing with fewer resources, using what we have a little smarter,” Reba said.

Cory Whitehurst, a freshman pre-optometry interdisciplinary studies major from Jonesboro, aids in the lab and the field sites for the research team.

“I didn’t know anything about water conservation research when I first started,” Whitehurst said. “Now I have an idea of the types of electronics that go behind finding out more about water, and have sort of an idea of how they work. I have also learned a little about the different types of soils and how they affect the water getting to crops.”

Whitehurst also understands the impact of the project.

“I believe this research is extremely important because farmers need to know what is in their water and what type of soil is best to help hold water,” he said. “It can help better their crop production.”

Reba’s research team has gained the support of organizations such as the Natural Resource Conservation Service, Cotton Incorporated and Entergy Corporation. She said this cooperation has helped her group move forward.

“I feel like we can really make some good strides in managing our water in the state,” she said. “What we do in this corner of Northeast Arkansas is very applicable to the Delta region at large.”