When birds and planes mix, the results can be deadly. Between 1990 and 2012, birdstrikes in the United States killed 23 people and injured 240, damaged nearly 12,000 aircraft, and slew more than 120,000 birds. But reducing the carnage may be as simple as letting the grass grow. Many airports have large expanses of turf, mowed regularly to a length of about eight inches. Aullwood 蜜柚APP Center and Farm in Ohio has partnered with the Dayton International Airport on a different approach, planting tallgrass prairie near the airfield instead of mowing or planting crops. The thinking is that this will deter the larger birds that can bring down a plane, like geese and gulls, since they tend to avoid longer vegetation, which hinders their ability to spot predators, says Charity Krueger, executive director of Aullwood 蜜柚APP. Smaller, less dangerous birds, such as sparrows and meadowlarks, tend to hide in the longer growth for safety. The Dayton airport aims to replace as many as 1,100...