Book Review: Dirt: The Erosion of Civilizations
Dirt: The Erosion of Civilizations by David Montgomery, is a fascinating read. I’ve been describing it to friends as Collapse written through the lens of soil. While Diamond’s work is more far reaching, Dirt benefits from the focus. Montgomery begins with an overview of what dirt is, including the various layers of it, then jumps right into history, and how each civilization has used (or abused) its soil. He covers the whole gamut of Western civilization, from Mesopotamia to Iowa, with stops in the Mayan Empire, Iceland, islands off Peru, and Rome during the Empire. He also discusses soil science, from the empirical terracing of the ancients to the more methodical scientific investigations of recent times.
I was most impressed by his melding of soil science with history. I found the book compelling in the same way as a train wreck you see in a movie–you know what is going to happen, but you still watch in horrified fascination. But this isn’t a movie, and the facts are clear–we’re currently “mining” our soil for food. Even with the addition of fossil fuel based fertilizers, top soil depletion is happening. This topsoil took thousands of years to form, and our farming methods are reducing it at a much faster rate.
Other civilizations, from Mesopotamia to the Mayans, have followed the path of topsoil depletion, and results were not pretty. When your soil is mined out, it takes a long time for it to come back (precisely how long is tough to say–soil rates do vary immensely because of climate and topography). When you don’t have soil, you don’t have food. When you don’t have food…
He only mentions worms a few times: Darwin’s famous last treatise on worms, “The Formation of Vegetable Mould, through the Actions of Worms, with Observations on Their Habits” where he estimated an acre of good English soil has “almost four hundred pounds of worms”; how worms plow the soil of the author’s yard, which he does not water; and how traditional plowing of soils does worms no good. His focus is not on vermiculture, but on the soil that is a complex living system, of which earthworms are a crucial part.
But anyone who keeps worms and sees the rich castings produced, or puts vermicompost on plants and watches them spring to life, can’t doubt that soils and worms are interrelated. Reading this book taught me much about soils and how they have been farmed and misused throughout human civilization, as well as the consequences thereof.
2 comments December 31st, 2008
