The Impact of Erosion on Ancient Civilizations: A Study of Dirt

M Clark: It was hard for me to believe how a book about soil erosion could be so fascinating. David Montgomery's Dirt: The Erosion of Civilizations provides an historical survey of the role of soil erosion and depletion and the resulting impact on people. He provides a variety of examples from all over the world and from countries both big and small.

The first chapter of the book explains soil in great depth, starting with it's various layers, how it is formed, the role of earthworms and how soil becomes depleted.

The next chapters then start discussing how mankind caused soil erosion and soil depletion starting with the activities of the very first people who practiced agriculture. The book then discusses soil in early civilizations including Egypt, Mesopotamia, Rome, and China.

The next chapters then deal with the role of colonization and slavery contending that agriculture performed by people who are not directly connected to the land will be short-sighted and lead to more soil erosion. He also discusses regions where families had such small parcels of land that they could no longer practice the fallowing needed to restore the soil. As a result, the soil became less...

Germany on Oct 17, 2023

Linda: All my friends wanted to read it!

United States on Aug 22, 2023

Susan: I thoroughly enjoyed reading this book. The soil and how we use it is as important to our survival as is climate change. It is a topic that should be far more widely discussed than it is now. This book helps to understand why this should be so.

United Kingdom on Nov 20, 2022

Paul Frobisher: This is basically everything about the relationship between soil, nature, plants, creatures and humans. How soil forms, how it works as a kind of mining system - extracting non organic nutrients, combining with atmospheric gases through photosynthesis to produce biology and nutrition.

The take home message is that if we neglect our soils, and continue to fail to recognise them at a strategic resource, our global civilisation is kind of doomed to fail. In the same way that many past civilisations found to their cost.

But the message of hope is that through understanding how soils work within an ecosystem we can actually turn things around. Though this will require a significant shift in farming techniques, landscape management and policy.

United Kingdom on Nov 17, 2021

A Brazilian Farmer: The author missed to point out, that in Brazil circa 80% of the farmers are adopting no Tillage, or zero Tillage on their farms, that's an area of 36,800,000 ha. 33% of the this area is under no tillage at least 20 years. Another point, the most valuable land in Mato Grosso, even in the Amazon Biome, are the ones that are under Agriculture for decades. Actually, farmers are building up the soil Fertility, through the years of farming, since the soil in our region are naturally really poor in nutrients. So using lime stones, fertilizers and good conservationists practices as no tillage, cover crops, or inter crops, corn with grass to improve the organic matter in the soil and recicle the nutrients, farmers instead of depleting the soil, are actually building condition to grow high yield crops. That's why we see a constant increase in yields here in Mato Grosso and elsewhere. Of course, there is plenty to do concerning about no tillage, crop rotation, cover crops and so on, but you have to keep in mind, that Brazilian farmers are not receiving any kind subsidies. Even though, that the farmers are preserving circa 25,6 % of the Brazilian territory in natural forest in their own...

United States on Sep 26, 2021

Ivan KinsmanIvan Kinsman: Once you start this book you get thoroughly engrossed in its topic. What I found most striking is how successive civilisations have mistreated their soil over time which was one of the main factors in their eventual demise. Throughout history mankind has got away with mining soil by moving to new land, but even marginal land is no longer available, which is the main reason why it is so important to sustain the soil we have now.
Montgomery makes a compelling case for implementing techniques such as regenerative agriculture, no-till, organic, adding any form of organic material for holding existing soil in place and rebuilding topsoil. He gives clear example of civilsations that have collapsed owing to their failures failing to implement these techniques (Easter Island, the Roman Empire being prime exampes), and sends the reader a clear message that our own long-term societal collapse is staring us in the face if we continue with industrial agriculture rather than transitioning towards more sustainable models that put soil health first.

United Kingdom on Dec 29, 2020

Ian M: This book was a great revelation for me, a person who thought he knew a bit about soil/earth/dirt. Well, I knew very little, it seems. The fascinating and frightening realisations that come with reading this book make it essential reading for anyone who has any feeling for the future of their society and offspring. As a geologist I really appreciate the style and depth of this book - it does not blind the reader with science and technicalities; it does not list the soil types and leave that as an explanation of the 'science of soil', which many other authors of papers and handbook entries tend to do. This book gets behind the subject, bringing it alive and punching home its dynamic, rather than merely descriptive, story. That's its great value. The discoveries of how soil works, Darwin's painstaking research, the fear of the Dustbowl, the fall of successive civilisations, the vital importance of that most important animal - the earthworm, all these make the book an absolute gem. I have both hardcopy and Kindle editions. The Kindle is useful for annotating passages to help me give talks and demonstrations in a geological and landscape context. My grateful thanks to the author. It...

United Kingdom on Dec 28, 2015

W. Walker: Perhaps the 3 most important challenges to contemporary man are 1)How to reduce dependence on non-renewable fossil and nuclear fuels,through reduced energy needs/person and development of realistic alternative energy sources 2)How to reverse the ever growing medical costs/person , due largely to delayed chronic illnesses and their inappropriate treatment, largely caused by unhealthy diets and lifestyles.3)How to reverse the rampant degredation of agricultural and forest soils that humanity largely depends on for their bodily sustenance and other important products. Of the 3, the last is the most important and by far the least appreciated by the general public, news media and education establishments. Of course, to a substantial extent, these 3 challenges are interrelated.Conventional mechanized and feedlot farming consumes considerably more inanimate energy(as well as agricultural land) than no and low-till agriculture and largely vegetarian diets complemented by grass-fed ruminant products. Spread out, functionally segregated, urban communities necessitates much energy expenditure(animate or inanimate) to get people and materials around, besides often eating up much previous farm...

United States on Nov 27, 2010

J. D. Halabi: In less than 250 pages Montgomery does a pretty good job of explaining what soil is, the history of what people thought about it, and the history of how people used (and mostly destroyed) it.

"It's like the earth's skin" he keeps saying. And as a non-scientist, the analogy is appealing.

When he deals with the past, the pattern he lays out is simple: a civilization uses up its soil, and moves on to other soil to use up; or a civilization uses up its soil, and the civilization declines.

Problem: we don't have much new soil to move on to, all the best stuff is in the temperate zone (the soil in the tropics is not as good and gets depleted much more quickly), and we don't really want to decline.

He makes the case for farming in different ways, smaller farms, less monoculture, drastic reduction in pesticide and fertilizer, more labor intensive farming, mulching/manure, contoured plowing, etc. etc. It is both radical, and reasonable.

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Units! Units are the worst part of the book.

He's only got four things to measure, but he makes it so hard to follow. We have depth of soil. That one he...

United States on Jun 27, 2010