CHURCHVILLE, VA—When people hear that I’m an advocate of high yield farming to feed the world and protect the environment, assertions of farm runoff into the rivers are raised to support charges against modern farming methods. Urban dwellers, even some of my rural neighbors, tell me their concerns about large-scale farming ruining our rivers “because the rivers are muddy.” They worry about even more soil erosion as farmers gear up to double food production over the next 40 years to feed a peak population of 9 billion people.