As the sky clears from a July downpour, you can bet on farmers doing two things. First, checking the rain gauge. Then, mentally calculating how long they can hold off irrigating again.

Mehmet Can Vuran, a University of Nebraska-Lincoln computer engineer, wants to give agricultural producers more information to make that decision. He's developing wireless underground sensor networks that should give agricultural producers precise, real-time data about soil moisture and other changing conditions.

Vuran has been awarded a five-year, $418,760 Faculty Early Career Development Program award from the National Science Foundation to support his research. This is NSF's most prestigious award for outstanding pre-tenure faculty and supports their development as researchers and teacher-scholars.

Wireless underground sensor networks consist of hundreds of sensors buried in the soil to collect data about soil moisture and composition, temperature and atmospheric changes. The idea, Vuran said, is to "let the soil tell us" when and how much to water.

Accurate, up-to-date soil measurements would enable agricultural producers to use water more efficiently. Vuran estimates that underground sensors could reduce irrigation as much as 25 percent depending on soil conditions and crop type. In Nebraska, which has more irrigated acres than any other state, such sensors could have significant economic and environmental benefits.

"Integrating wireless sensor network solutions with agriculture has huge potential to improve crop yields as well as decrease irrigation costs significantly," he said.

Vuran also is designing network protocols that enable the sensors to transmit information through the soil to a center-pivot irrigation system. The pivot's control system would use this information to determine when to turn on the water and how much to apply.

The ability to harmonize farming operations with actual soil conditions would give wireless underground sensor networks a major advantage over above-ground weather stations that only monitor atmospheric conditions. An underground network also would be more reliable than a wireless weather station, whose signal can interfere with other farm equipment or get blocked by trees and other obstructions, Vuran said.

His research shows potential to transform wireless communications in constrained environments. Soil, especially when wet, limits the sensors' transmission power. Vuran's challenge is to create network protocols and communication devices smart enough to adjust to the dynamic conditions of soil or water. These advancements could expand the use of wireless underground sensor networks to applications as diverse as irrigating golf courses and playing fields or monitoring underground oil pipes.

Since joining UNL in 2007, Vuran has collaborated with Suat Irmak, associate professor of biological systems engineering, to test real-world applications of wireless underground sensor networks at the South Central Agricultural Laboratory near Clay Center.

Vuran's CAREER award also provides support for a wireless networking solutions workshop for teens, which will be offered through the Big Red Summer Academic Camps hosted by Nebraska 4-H and UNL.

"We want budding farmers to see how they can use computer science and engineering to solve agricultural problems in their communities," Vuran said.