Dirt, soil, call it what you want—it's everywhere we go. It is the root of our existence, supporting our feet, our farms, our cities. This fascinating yet disquieting book finds, however, that we are running out of dirt, and it's no laughing matter. An engaging natural and cultural history of soil that sweeps from ancient civilizations to modern times, Dirt: The Erosion of Civilizations explores the compelling idea that we are—and have long been—using up Earth's soil. Once bare of protective vegetation and exposed to wind and rain, cultivated soils erode bit by bit, slowly enough to be ignored in a single lifetime but fast enough over centuries to limit the lifespan of civilizations. A rich mix of history, archaeology and geology, Dirt traces the role of soil use and abuse in the history of Mesopotamia, Ancient Greece, the Roman Empire, China, European colonialism, Central America, and the American push westward. We see how soil has shaped us and we have shaped soil—as society after society has risen, prospered, and plowed through a natural endowment of fertile dirt. David R. Montgomery sees in the recent rise of organic and no-till farming the hope for a new agricultural revolution that might help us avoid the fate of previous civilizations.
Montgomery (King of Fish), a geomorphologist who studies how landscapes change through time, argues persuasively that soil is humanity's most essential natural resource and essentially linked to modern civilization's survival. He traces the history of agriculture, showing that when humans exhausted the soil in the past, their societies collapsed, or they moved on. But moving on is not an option for future generations, he warns: there isn't enough land. In the U.S., mechanized agriculture has eroded an alarming amount of agricultural land, and in the developing world, degraded soil is a principal cause of poverty. We are running out of soil, and agriculture will soon be unable to support the world's growing population. Chemical fertilizers, which are made with lots of cheap oil, are not the solution. Nor are genetically modified seeds, which have not produced larger harvests or reduced the need for pesticides. Montgomery proposes an agricultural revolution based on soil conservation. Instead of tilling the land and making it vulnerable to erosion, we should put organic matter back into the ground, simulating natural conditions. His book, though sometimes redundant, makes a convincing case for the need to respect and conserve the world's limited supply of soil. Illus. not seen by PW.