A trio of Irish high-schoolers nabbed the top prize in this year's Google Science Fair with a project that speeds up crop growth by tapping into the naturally cozy relationship between soil microbes and plants.
After 11 months of experiments, the three 16-year-olds—Ciara Judge, Émer Hickey, and Sophie Healy-Thow—found that seeds treated with bacteria sprouted 50 percent faster than untreated seeds did. At harvest, the microbes increased barley and oats yields by as much as 70 percent. (See "Why Tiny Microbes Mean Big Things for Farming.")
The improved sprouting speed is instrumental to farmers in Ireland, where seeds can rot in the damp soil before sprouting, Hickey said. The trio hails from Cork County, the agricultural southern tip of the country.
But the project really kicked off in Hickey's own backyard.
"Émer and her mom were gardening, and she noticed nodules on one of their pea plants," Healy-Thow said. "She brought that into school, and our teacher told us it was bacteria."
The bacteria act as an early warning system for the plants, kickstarting growth. When the microbes sense the presence of compounds called flavonoids on plants, they begin to build nodules, swellings on roots that house bacteria able to convert atmospheric nitrogen into forms the plant can consume. The presence of the nodules then tells the plants it's time to grow faster.
It's an age-old, mutually beneficial relationship that scientists have long applied to agriculture, says Jeff Dangl, a biologist at the University of North Carolina at Chapel Hill.
The trio's experiment focused on three cereal crops found in diets around the world and used a strain of root microbes, Rhizobium bacteria, that is ubiquitous in soils. But the buck doesn't stop with those specific crops or bacteria.
"The great thing about our theory is [that] any crop that contains a flavonoid can trigger bacteria. It'll work the same," Judge said.
Since soil bacteria are naturally occurring, the teens emphasized that the process of inoculating seeds to increase plant growth would be feasible and inexpensive. In fact, similar commercial products are widely available.
"Companies such as Monsanto have been doing this sort of work for a long time. You can actually go into most gardening stores and buy bacteria in powder form that you can apply to your own plots," said Jack A. Gilbert, a microbial ecologist at Argonne National Laboratory in Illinois.
The next steps are refining the process to foster the relationship between plants and bacteria more effectively in specific pairings, says Gilbert. (Read "The Next Green Revolution" in National Geographic magazine.)
With interest from the European Commission and a patent to apply the research to brewing in the works, the trio says they want to continue their project, including investigating "what's happening inside the seeds"—but outside Hickey's backyard.
Other Google Science Fair winning ideas include robots inspired by fruit flies and bioreactors that clean up waste from the processing of oil sands. National Geographic is a Google Science Fair partner, sponsoring a trip to the Galàpagos Islands for the grand prize winners.
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