Wireless nitrate soil sensor could cut fertilizer use
A University of Oregon spinout company that has developed a wireless soil sensor to detect nitrate levels in fields that could help farmers reduce fertilizer use by up to 30 percent, has been awarded Oregon BEST commercialization funding to fast-track the product to the marketplace.
Because plants can absorb only so much nitrogen, approximately 30 percent of the fertilizer applied to North American soils is wasted due to over-application and runoff. With U.S. farmers spending $12 billion annually on fertilizer, the new supramolecular sensor technology, discovered by accident by chemists at the UO, could lead to significant savings in fertilizer purchases, as well as in labor and fuel costs associated with fertilizer application.
It could also help reduce pollution from fertilizer runoff.
"In addition to the potential economic savings for farmers, our sensors will also help reduce groundwater pollution caused by excess nitrates that flow from cultivated fields into streams, lakes and oceans," said Calden Carroll, CEO of SupraSensor Technologies. "Excess nitrates are what trigger algal booms that deplete oxygen levels and create dead zones in the water where nothing can live."
Carroll, who earned his PhD in chemistry from the UO in 2011, said nitrates are problematic in fertilizers because they are water soluble, so over-application can lead to nitrates being leached from the soil and into the water system.
The problem is so widespread that the National Academy of Engineering has identified managing the nitrate cycle in agriculture as one of 14 "Grand Challenges" for the 21st century.
Carroll discovered the molecule now used in the sensor "by accident" when he was a graduate student studying supramolecular chemistry—the interactions between molecules—with UO chemistry professors Darren Johnson and Mike Haley (all of whom are co-founders of SupraSensor Technologies).
"Calden's initial result was a happy accident," said Johnson, who is also an adjunct professor at Oregon State University. "We were trying to create a molecular probe to visualize the movement of chloride—not nitrate—through cells to aid research into drug discovery and understanding chloride transport mechanisms in general."
Although the research team knew they had discovered a molecular marker specific for nitrate, it wasn't until later that they realized the implications of the discovery in agriculture and launched the new company.
"How to take a chemical interaction and transduce an electrical signal has been a long-standing problem," said Carroll. "But when nitrogen binds to the molecule we developed, it fluoresces a cool color, and we're able to harness that electronic response to measure nitrate levels."