Forty-five irrigated farm operations across Kansas, Oklahoma and Texas are testing whether satellite evapotranspiration data can sharpen irrigation decisions as the Ogallala Aquifer region's water supplies decline.

The five-year, USDA-funded Satellite Enabled Resilient Ag Project, known as SatRAP, began in 2025. It brings together researchers from Kansas State University, the University of Kansas, Oklahoma State University, Texas Tech, Texas A&M University and West Texas A&M University, alongside OpenET and NASA-affiliated scientists.

The project runs 15 participating operations in each of the three states, plus one demonstration farm per state. Most are irrigated fields in areas where producers already face changing water availability or water-use policies. Crops in the trial include corn, sorghum, soybeans and cotton.

What is being tested in the field?

Researchers are retrofitting fields with commercially available technology while producers run normal operations. The kit list includes:

• Soil moisture sensors
• Water meters
• Localized weather stations
• Autonomous irrigation equipment
• Eddy covariance towers
• Sensors mounted on center pivots that collect data as the pivot moves across the field

Those ground-level measurements validate satellite-based estimates of water use, largely through OpenET, an online platform that uses satellite data to estimate evapotranspiration — the amount of water leaving a field. OpenET is already available to the public at no cost.

Why isn't the satellite data ready for daily decisions?

Jonathan Aguilar, an Extension irrigation specialist at K-State and SatRAP researcher, is blunt about the technology's current limits.

"It is not yet in the stage where it can be used for daily decision making of irrigation," Aguilar said. Current data typically arrives with a three- to four-day delay.

He wants that to change: "We are hoping that we will get to the point that it's almost like a regular weather forecast, wherein you have the data from the past 24 hours, and some projection of the data in the next three to four days ahead of time."

Technical gaps remain. Cloud cover interferes with satellite observations, and satellite estimates of water use rely on proxy measurements such as temperature rather than directly measuring water leaving a field.

"That means that we have to make sure the equation or procedure really captures the data, and that's where the land-based sensors are going to work well," Aguilar said. Researchers are also comparing water meter readings against satellite estimates of applied water.

Can the data change field decisions?

The core challenge is turning data volume into usable decisions, according to Susan Metzger, SatRAP program director, who also directs the Kansas Water Institute and leads strategic interdisciplinary program development at Kansas State University.

"We're data rich and information poor, and so I think this is only reinforcing that it's not necessarily about more data; it's about taking good data and translating that into good decisions in real time," Metzger said.

She frames SatRAP around one question: how can producers stay productive as water becomes increasingly limited across the High Plains?

"Every inch of water that we apply is critically important, and where and when you apply it needs to mean something. It needs to result in good production, and precision agriculture is the way that we can get there," Metzger said.

For now, irrigation decisions stay with the producer. Aguilar noted a practical limit of existing sensors: "Many of the soil moisture sensors are able to help make a decision on when to irrigate, but probably not how much to irrigate."

Some participating producers are becoming more mindful of when they irrigate. But it is too early to claim water savings.

"But we don't have enough information to make any substantial claim that they are pumping less or more," Aguilar said.

Metzger stressed the project is not meant to replace growers' own knowledge.

"If you were to take all this technology away, the smartest person in the room is the person that's been managing that land in their family for as long as they have been," Metzger said. "We're hoping to learn with them to improve that."

Over the remaining years of the five-year project, running to 2030, researchers will use field measurements and satellite data to identify which tools deliver useful information for irrigation management as water supplies tighten. Farmers outside the trial can already access OpenET free of charge and watch SatRAP's findings as validation work progresses.