MILLFIELD, Ohio — Clad in high-visibility clothing, Badger Johnson scatters a flaming mixture of gasoline and diesel on the ground around him to ignite the forest underbrush. Johnson isn’t an arsonist. He is a certified prescribed burn manager, working to clear out invasive plants and enhance the forest ecosystem at Solid Ground Farm. With Weston Lombard, executive director of Rising Appalachia and co-owner of Solid Ground Farm, Johnson organiz…