CURWOOD: Our land – our Home Ground is soil. And soil – that humble, vital basis of all the greenery we depend on - is the subject of this excerpt from the book “Home Ground, Language for an American Landscape”.

Nature writer Barry Lopez and fellow author Debra Gwartney gathered lyrical descriptions of landscape features in this book. Today Barry Lopez explains – soil.

LOPEZ: Soil. Erosion, volcanic eruption, earthquakes, floods, tectonic grinding, landslides, and other natural forces act continuously on the earth's crustal rock, creating various types of debris—gravel deposits, mudflats and the tidal estuaries of creeks, cobble terraces, and beaches of black lava sand. When chemical agents, such as phosphorus and nitrogen, infuse this debris, and biological entities including microbes and earthworms work material into it organic enough to support plants, it becomes soil. A soil that is chemically or organically exhausted, that's been pulverized or become deeply parched, that has been invaded by decomposing rock, or that's been fowled by sewage or industrial pollution to the point where it no longer can support plant life, is called dirt.

CURWOOD: That's writer Barry Lopez, who together with Debra Gwartney, created "Home Ground: Language for an American Landscape."