Dirt

In a fast-paced, accessible yet sweeping synthesis, renowned geologist and published trade author David Montgomery examines human history through the lens of agriculture and how increasing intensification of farming undercut the foundation civilizations around the world whose use of soil outstripped the natural supply. Drawing from archaeology, geology, soil science, and history, Montgomery shows that the life span of civilizations can be determined from the way they treat their land. Dirt is our most under-appreciated yet most essential resource. Soil erodes much more quickly than it forms, but erosion is inevitable and is hastened by our widespread agricultural practices and other abuses. Each year, the world now loses some 24 billion tons of topsoil. Montgomery describes how ancient societies - the Greeks, Romans, Maya, etc. - repeatedly exhausted their land at a pace set by their technological sophistication and hastened their downfall and created populations of refugees. Societies that run out of dirt run out of options to survive, but Montgomery holds out hope that recent interest in no-till and organic agriculture, practices that protect soil and water, will allow farsighted societies to follow a more sustainable path and cling to the ground beneath them.