December 5, 2009 at 8:14 pm #227PublisherModerator
Dirt, soil, call it what you want – – it’s everywhere we go. It is the root of our existence, supporting our feet, our farms, our cities. This fascinating yet disquieting book finds, however, that we are running out of dirt, and it’s no laughing matter. An engaging natural and cultural history of soil that sweeps from ancient civilizations to modern times, Dirt: The Erosion of Civilizations explores the compelling idea that we are – – and have long been – – using up Earth’s soil. Once bare of protective vegetation and exposed to wind and rain, cultivated soils erode bit by bit, slowly enough to be ignored in a single life-time but fast enough over centuries to limit the life spans of civilizations. A rich mix of history, archaeology, and geology, Dirt traces the role of soil use and abuse in the history of Mesopotamia, Ancient Greece, the Roman Empire, China, European colonialism, Central America, and the American push westward. We see how soil has shaped us and we have shaped soil – – as society after society has risen, prospered, and plowed through a natural endowment of fertile dirt. David R. Montgomery sees in the recent rise of organic and no-til farming the hope for a new agricultural revolution that might help us avoid the fate of previous civilizations.December 5, 2009 at 8:21 pm #316PublisherModerator
Treating people like dirt suggests they are common and worthless. That saying will have to change. In Dirt: The Erosion of Civilizations, David R. Montgomery uses history to show that commonplace dirt is an increasing scarcity, priceless in supporting the world's population.
How are we to feed the world? By first looking at the past. Therein lie the clues into what we are doing wrong today that needs to be changed. This Professor of Earth and Space Sciences reveals the fundamental reason for the demise of past civilizations. Survival of the human society always depended on how people treated their valuable topsoil. Montgomery warns that "modern society risks repeating mistakes." Using cored soil samples, and written records from ancient times to current times, he studied the middle east including ancient Iraq, thought to be the cradle of civilizations; ancient Roman and Greek farmers; southern United States; Soviet Union; sub-Saharan Africa; and Brazil's Amazon.
In the past, when topsoil disappeared, people moved onto new unbroken soil. Europeans turned to the colonies. Today the Amazon forest desiccation demonstrates that soil's inadequacies at growing food over the long-term. With no new lands to discover on planet Earth, these solutions are no longer viable.
In the past, when agriculture could no longer feed society, civilization peaked, disease and starvation ravaged the population, social and political conflicts arose, destroying the civilization. Today we see the same problem of hungry people defined as environmental and political refugees.
Montgomery discovered two important factors that occur where the society fails to feed its population: first large farms created for economics, and second absentee landowners. Both of these factors occur in our current agricultural sector.
Large farms based on economics encourage soil mining or degradation. "Large" farms existed 2000 years ago with peasants and/or slaves working the soil. Our small traditional farm with holdings of four quarters, then six, then eight have disappeared replaced by large farms with sections of land, not quarters. The first priority is income. Contrast this short-term goal with the almost non-existent long-term concern for soil health and enrichment.
Absentee landowners existed in ancient Rome with overseers and tenant farmers paying a percentage of their crop to the landowners. Again, the first priority is income with negligible concern for soil building and health. Rental of Saskatchewan private farmland hovers around 30-40% according to Statistics Canada, fairly static but trending upward. Much of the rented land is owned by farming wives who have outlived their husbands. Then we have new landowners who are changing the rental percentage: First Nations who used land claims to buy farmland, investor groups intent on making a profit buy farm land, and nations intent on food security buy farm land in other countries.
Today, absentee landlords are promoted as professional managers. This is an oxymoron. Only people who directly work the soil can be professional managers. Groups investing in farmland looking for returns of 5-6% are soil miners or money managers, not soil builders.
Montgomery points out that professional managers existed in Greece during the fourth century BC. Wealthy landowners employed superintendents to professionally manage the farm labourers. Xenophon advised these owners to know "what crops grow best upon it; and we may even learn from the weeds it produces what it will best support". He advised farmers to use manure and plow in burned crop stubble to enrich the soil.
Montgomery paints history with a different brush. When we understand the condition of the soil, we can see why history moved as it did with the fall of civilizations. At this point, with the two important factors prevalent in agriculture, our civilization is headed for a fall too. What must we do differently?
First off, Montgomery warns that farming as a business cannot work. Focusing on the bottom line is a short-term consideration. Today's tenant farmer and larger farmer do not calculate the economic benefits of soil conservation and soil enrichment. To survive, our society needs long-term soil building to be factored into the bottom line. History shows it is easier to deplete soil than to build it. Given the time it takes to rebuild soil and the lack of a possible alternative to healthy soil makes soil exhaustion and soil erosion an uncalculated economic costs. Montgomery found farming practises where soil conservation worked and fed high number of people per acre.
Secondly, Montgomery says only naivety believes producing cheap foods will eliminate hunger. We already have cheap food. Food distribution, social and political institutions cause as much hunger as food shortages. Environmental refugees exist because new political boundaries and taxes have compelled people to change their relationship to their land.
Thirdly, genetically modified crops will not feed the world. Montgomery believes the threshold to increasing crop yields has already been reached. To focus on single-crops proliferation also creates a shaky foundation for feeding the world. Montgomery warns of limiting the gene pool and the risk of releasing superplants into our environment. Numerous field trials have discovered that higher yields are not guaranteed with genetically modified crops. The USDA also discovered that pesticide use is not reduced with genetically modified crops.
Fourthly, most of the planet has poor soil where humans must adapt farming to the soil. In the past, we have adapted farming to meet political demands. Agricultural policies were forced on developing countries with tropical soils and/or poor soil to grow cash crops for export. These monoculture crops have destroyed the soil and the ability of people to feed themselves. When countries can no longer feed their people with local food, intense political and social conflicts arise as in the Middle East. When will these conflicts spill over into developed countries?
Slight global warming of a 1°C increase in temperature reduces rice yields by 10%. Montgomery says projections are similar for wheat and barley. What will happen with crop yields if there is a 1 to 5° C increase in temperature? But it is not just crop yields. With increased temps will come increased higher intensity rainfall producing additional soil erosion and in some marginal agricultural lands drought.
Soil erosion must not continue to exceed soil production. The difficulty lies in the time it takes to rebuild soil. Soil erosion occurs faster than soil formation especially the way the people manage their gardens, lawns, and conventional crop land. It takes 500 years to produce 1 inch of topsoil. With earthworms 1 inch can be produced in 100 years. History shows us that animals are essential to soil health. Forty cows can re-fertilize one quarter of land. Unfortunately, our good intentions are misdirected. Instead we focus on huge specialized grain farms, and the methane produced by cows rather than the cows' valuable contribution to soil building.
For instance, in the fall, we clean our gardens of the season's past growth, and rake leaves from lawns. Unfortunately, our good intentions are again misdirected. We are depriving the soil and its microbes and microfauna of food. Either leave the plants and leaves on top of the ground or mulch and spread. If you can't mulch, remember in time the garden and lawn does its own mulching. Even for organic farmers, ploughing down peas and clover into the ground is not as good as leaving the plants on top. Mulching and harrowing the peas and clover would better retain moisture.
As gardeners and farmers worldwide, we continue to till, use pesticides which exterminates microbes and microfauna important to soil formation, focus on conventional short-rotation and on single crop farming. Even irrigation is destructive. Irrigation destroys soil by increasing salts. In times before Christ, the Middle East grew crops through irrigation; "by 2000 BC, crop yields were down by half." All these current methods are not good for soil formation, severely restricting the soil's ability to rebuild, and minimize soil erosion.
Montgomery says research proves that huge mechanized farms are not more efficient and profitable than smaller traditional farms. Larger farms spend more per unit of production. Smaller farms are more efficient because these farms account for health, environment and social costs. Small farms can produce more food from the same amount of land. In 1992, US AG Census, discovered small farms grew 2-10 times more per acre than large farms. Even though large farms can produce greater yields for one crop (monoculture), diversified polyculture farms, often small farms, produce more food per acre based on the total output from several crops.
According to Montgomery, capital intensive agriculture will never feed the world. Large mechanized crops don't work because new equipment tills to a deeper depth. The huge specialized grain farms incorporate no terracing, no contour cultivation, no hedge rows, no tree breaks, and no use of livestock.
We cannot ignore how our soil is treated because the cost of soil abuse will be borne by all. In the past, kings with all their gold could not even buy food when food became scarce. Montgomery has solutions for urban people and for farmers all over the world. Increasing inputs will not help increase crop yields as topsoil thins and disappears. Montgomery's well-researched book demonstrates soil as an investment inheritance and farming as the living foundation for material wealth. Our society will grow and prosper only as long as our topsoil deepens and enriches. When we deny our topsoil, degrade it, then we will sacrifice our future ability to feed our global society, and our very existence.
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