Though the title says Dirt, it should actually say Soil, as this book is about how numerous civilizations destroyed themselves by adopting unsustainable farming practices that eventually destroyed their land. The author examines the histories of England, Roman Empire, ancient Greece, pre-colonial Ethiopia, Mesopotamia, Pharaoic Egypt, continental Europe, Communist Russia, the antebellum South, Colonial New England, and China. The conclusions he draws from all are the same, agricultural practices driven by short-term profit led to long-term soil erosion and depletion. The latter created poverty, inducing emigrations, which led to civil strife, war, and gradual collapse. So this book does live up to its subtitle, it is a history of human civilization as told from the viewpoint of soil erosion.
As a work of nonfiction, its contents apply well to history, economics, geology, ecology, and anthropology, along with agriculture. As a commentary, it is quite objective and its points are well-conveyed. As reading material; it flows quite nicely and the chapters are easy to digest. A great book overall.