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.")