The phosphorus and calciul of the earth build our skeletons and nervous systems. Everything else our bodies need except air and sun comes from the earth.
Nature treats the earth kindly.
Man treats her harshly. He overplows the cropland, overgrazes the pastureland, and overcuts the timberland. He destroys millions of acres completely. He pours fertility year after year into the cities, which in turn pour what they do not use down the sewers into the rivers and the ocean. The flood problem insofar as it is man-made is chiefly the result of overplowing, overgrazing, and overcutting of timber.