His research addresses the evolution of topography and the influence of geomorphological processes on ecological systems and human societies. His published work includes studies of the role of topsoil in human civilization, the evolution and near-extirpation of salmon, morphological processes in mountain drainage basins, the evolution of mountain ranges, and the use of digital topography. He has conducted field research in eastern Tibet and the American Pacific Northwest.
In 2008 Montgomery received a MacArthur Fellowship. His book, Dirt: The Erosion of Civilizations won the 2008 Washington State Book Award in General Nonfiction.
Webcast sponsored by the Irving K. Barber Learning Centre. Author David Montgomery has discovered that the three-foot-deep skin of our planet is slowly being eroded away, with potentially devastating results. In this engaging lecture, Montgomery draws from his book 'Dirt: The Erosion of Civilizations' to trace the role of soil use and abuse in the history of societies, and discuss how the rise of organic and no-till farming bring hope for a new agricultural revolution.
“Many factors may contribute to ending a civilization, but an adequate supply of fertile soil is necessary to sustain one ... civilization’s survival depends on treating soil ... as something other than dirt.”
this article is a Book Review by Jim Burns of one of the recommended books in the reading list for this module:
“Dirt - The Erosion of Civilisations” David Montgomery
Courtesy of samaralectures.com
This is not a new book, but I believe it to be one of the most important I have read in recent years.
It is certainly one of the most impressive. David R. Montgomery is Professor of Earth and Space Sciences at the University of Washington, but this book has none of the verbose obscurantist terms so common in academic writing. It is one of the most accessible pieces of writing on the subject I’ve encountered. In the first few pages Montgomery gets right down to business with the premise that few people today know much, if anything, about soil.
He touches on how soil erosion led to the demise of ancient civilizations and social collapses up to our own times; the refugees of the 1930s US Dust Bowl, 1970s Sahel, and today’s Ama- zon Basin.
“... the key lesson is as simple as it is clear: modern society risks repeating mistakes that hastened the demise of past civilizations ... few places pro- duce soil fast enough to sustain agricultural growth over human time scales, let alone over geological time. Considered globally, we are slowly running out of dirt.”
He gives a wonderfully simple breakdown of how soils form and of what they are comprised, citing Darwin’s work on worms and its modern verification, nitrogen fixation via symbiosis between bacteria and plant hosts, the role of climate, tem- perature, and rainfall, lamenting: “So far ... few human societies have produced cultures on sustaining the soil, even though most discovered ways to enhance soil fertility. ... Soil truly is the skin of the earth – the frontier between geology and biology,” adding that conventional agriculture is “... literally skinning our planet.”
He admits to early personal experiences that shaped this view: “Growing up in California’s Santa Clara Valley, I watched the orchards and fields between Palo Alto and San Jose turn into Silicone Valley,” and learned “... that preparing a building site means carting the topsoil off to a landfill,” now “Completely paved, Silicone Valley won’t feed anyone again for the foreseeable future.”
His narrative runs from the last Ice Age through the transition from hunting and gathering to cultivation of the ancestors of modern grains, domestication of ani- mals, to the salinization that destroyed the Mesopotamian cultures. He looks at the difference between that event and the continuity of Nile Valley agriculture until the nineteenth century changes to irrigation, brought by the demand for cotton, which led to a hydrological destruction of what may have been the most stable agricultural system on the planet.
The agricultural history of ancient Asia is treated similarly, as is Central America, Greece and Rome. Classical writers are cited on soil testing, and agricultural systems used.
The practice of absentee landlords, farm managers, and slave labour are all seen as contributing to the decline of both the Roman republic and empire. “Rome did not so much collapse as consume itself,” both at home and in its prov- inces, especially in North Africa. He contrasts this with the success of Andean farm- ers in comparison to those of Central America and the US Southwest and touches on Amazonian terra preta and similar practices in northeast Thailand.
He shows Neolithic and Medieval forest clearing in Europe, the role of first the church and then early 17th century capitalists as the main landowners, in clearing common land to promote private ownership, leading to the decline of soil fertility, and a resultant lowering of European nutrition, a constant rise in food prices and repeated periods of famine.
The colonization of the Americas, the Potato Famine, the spread of the worst ex- cesses of poor farming techniques (despite abundant warnings by soil husbandmen of the times), and the 20th century political motivation behind the denial of equita- ble land distribution laws in poorer countries by wealthier neighbours to benefit multinational corporations, are all covered in some detail.
For every era, in every nation, Montgomery acknowledges those who experi- mented, found ways to revitalize soil without long-term deleterious effects. He “Dirt—The Erosion of Civilisations” castigates government bodies and political leaders alike for failure to respond to warnings of soil exhaustion, reduced crops, and future costs when sensible meas- ures were not taken.
He quotes the Report of the Commissioner of Patents for the Year 1849, part 2, Agriculture, presented in the US Senate, 1850: “There ap- pears to be no government that realizes its duty ‘to promote the public welfare’ by ... impressing upon them the obligation which each cultivator of the soil owes to posterity, not to leave the earth in a less fruitful condition than he found it.” He is scathing of Soviet Premier Khrushchev’s decision to rip up forty million virgin acres between 1954 and 1965, despite scientific advice warning of similar effects to the US Dust Bowl on the 1930s.
The results included the drying of the Aral Sea, dust storms that dumped a hundred million tons of salt and silt on Rus- sian farms, the collapse of both fishing and agriculture in the region, and deserti- fication of two-thirds of the arid areas of Kazakhstan, Uzbekistan, and Turkmeni- stan.
He warns that similarly, today, “The Canadian and American prairie is al- ready marginal as agricultural land in its western extent.” Montgomery explores the “Green Revolution”, with its chemical fuelled high- yield grain varieties, and shows how it failed to feed the hungry as poor peas- ants could not afford the fertilizers and pesticides, population growth out- stripped any benefits, and natural soil fertility declined.
He takes us all to task for our insane overuse of oil “eighty million barrels a day – enough to stack to the moon and back two thousand times,” and the constant rise in food costs, “If the poor can’t afford to buy food, increased harvests won’t feed them.” He takes a big stick to US state legislators who allowed toxic wastes to be “recycled” and sold as farm fertilizer.
He names companies – Cenex, ALACOA, and others. However, Montgomery reserves his greatest contempt for biotech “solutions”, pointing to a study that shows genetically modified soy beans produced smaller harvests than natural seeds, and another by the USDA, that found no reduction in pesticide use associated with genetically engineered crops. He also warns of movement of inbuilt sterility from GM seeds to traditional crops, “with catastro- phic results.”
There are short, in-depth studies of island societies: the Pacific islands of Rapa Nui, where the collapse of society due to loss of tree cover has been closely documented by Jared Diamond; Mangaia, where loss of topsoil, fruit bat and bird extinction, and warfare, brought a dramatic population decline; and Tikopia, which, despite a larger population, ended slash-and-burn methods, adopted a pattern of sustainable gardening with multi-storied tree and under- story crops, ended intensive pig production, and developed a religious ideology that preached, and practiced, zero population growth.
The catastrophic agricultural histories of Iceland, Haiti, and Cuba follow, and provide food for thought for anyone planning social, and agricultural, change in the years ahead. Only Cuba gets a bouquet for the turn-around effected between the mid-1980s and the present. “... it is ironic that in retreating from the socialist agenda, this iso- lated island became the first modern society to adopt widespread organic and biological intensive farming.” Montgomery then documents the history of organic farming from the 1920s ideas of Sir Albert Howard and Edward Faulkner.
Faulkner regarded ploughing as causing more problems than it solved, and proved his theories correct with practical experiments, publishing his work in Ploughman’s Folly (1943). Their ideas gained ground until the end of World War II when they were dumped in favour of the use of cheap artificial fertilizer, left over from weapons produc- tion. He bemoans the fact that, globally, “Faith in the power of chemicals to catalyze plant growth replaced agricultural husbandry ... practices and traditions developed and refined over thousands of years ... agro-chemistry became con- ventional farming, and traditional practices became alternative farming.”
Montgomery clearly believes in the benefits of no-till methods, quoting a pleth- ora of studies from the US, Canada, and New Zealand. Nor is he merely an arm- chair observer. He cites an experiment on his own front lawn, fed with home- made “soil soup” brew and coffee grounds from a local shop, resulting in rich organic matter, ploughed by a huge worm population.
He applauds the work of “Ongoing soil degradation and loss present a global economic crisis that, although less dramatic than climate change or a comet impact, could prove catastrophic nonetheless, given time.”
All organic movements and natural systems farmers for providing polycultures that reduce pests, provide their own nitrogen, and use species appropriate to the local environment. On relative costs he mentions a 1974 study by Washington University that found fourteen organic farms had produced roughly the same income per acre as fourteen conventional farms, and later studies showing that lower production costs had offset slightly smaller harvests in others. “Industrial agro chemistry is a societal convention and not an economic imperative. ... No till,” he says, “could provide one of the few relatively rapid responses to help hold off global warming.”
His conclusion on or- ganic versus conventional farming is clear: “Over the long run, intensive organic farm- ing and other non-conventional methods may prove our best hope for maintaining food production in the face of population growth and continuing loss of agricultural land.” But Montgomery also hands out some dire warnings. He shows that, since the end of World War II, Asia, Latin America, Eastern Europe, and Africa have all lost their ca- pacity to produce sufficient grain to feed their populations. “Today North America, Australia, and New Zealand are the world’s only major grain exporters.”
And we have seen in the last decade just how precarious is Australia’s grain production capac- ity. He cautions China on its loss of croplands to erosion, and that, “Despite growing use of synthetic fertilizers, Chinese crop yields fell by more than ten percent from 1999 to 2003.” He comments on the dwindling global grain reserve stocks - in 1980, the lowest ever at just 40 days supply (2010 supply is 70 days) and repeats agricultural economist Lester Brown’s early 1980s warning that “modern civilization could run out of dirt before it runs out of oil.”
He takes a look at various pundits’ ideas on just how many people the planet can sustain. The US National Conference of Catholic Bishops – 40 billion. “Green Revolu- tion” Nobel Prize winner Norman Borlang – 10 billion. Paul and Anne Ehrlich – 3 billion. Ted Turner – 400 million. Montgomery’s own view is that even if a full planetary photosynthetic production could be reached “with the same efficiency as the 40 percent now devoted to supporting humanity, we could support fifteen billion people – and share the planet with nothing else.” (My emphasis.)
His own opinion is very clear: “market efficiencies can be effective drivers for most social institutions. Agriculture is not one of them.” He points out what all economic rationalists turn a blind eye towards, that Adam Smith himself admitted that govern- ment regulation is required to force markets to desirable social outcomes, and that the same economists totally ignore resource depletion.
Montgomery concludes with, “... any combination of political turmoil, climatic ex- tremes, or resource abuse can bring down a society ... we face the potential conver- gence of all three in the upcoming century...” He then lays out his ideas of what can, should, and must, be done. Much if it is precisely what Permaculturists and other sus- tainable agriculturists are doing today both at home and in developing countries.
His final words: “Many factors may contribute to ending a civilization, but an adequate supply of fertile soil is necessary to sustain one ... civilization’s survival depends on treating soil ... as something other than dirt.”
I believe his excellent book also makes it clear that global citizens cannot wait on, nor trust, national, state, or regional governments to act responsibly. It is a call for all of us to act responsibly now, in whatever way within our power, for the sake of future generations. David R. Montgomery.
Dirt: The Erosion of Civilizations. University of California Press p/b 2008.
Terra preta soils are found mainly in Amazonia, estimate that they cover at 0.1 to 0.3%, or 6,300 to 18,900 square kilometres (2,400 to 7,300 sq mi) of low forested Amazonia; but others estimate this surface at 10.0% or more .
Above: A hillside cut for slash and burn in Vietnam Courtesy: http://www.tropag- fieldtrip.cornell.edu/Thurston_TA/pburning.html Above: Soil erosion on cassava plantation in Thailand. Photo from Creative Commons ... Courtesy: www.ddimick.typepad.com
Above: Crucified Land, by Alexandre Hogue (1898–1994). Oil on canvas, 1939. Courtesy of Gilcrease Museum, Tulsa, Oklahoma.