When Greg Scott teaches people about soil health, the front row better beware. The soil scientist from Oklahoma hauls around a rain simulator that holds bins of soil you’d see on different types of farmland. When he flicked his contraption on in Norman, Oklahoma, recently at a journalist’s conference, shoes and notepads got wet. But what didn’t get very wet was the bin of dirt that mimicked tilled land, a common method of digging and stirring up the soil before planting.