Canada and the World

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19 November 2010

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Arable Land is Becoming Scarce

 

Soil is a commodity that is in a diminishing supply

and its growing scarcity comes at just

the time when increased food production is needed

 

Peak oil is the point at which the world has used up half its supply of oil. Depending upon who you listen to, the planet:

• has already passed peak oil and is using up the second half’s supply;
• is about to pass the half-way point, or,
• has nothing to be worry about because there are plenty of energy alternatives to switch to once the oil is gone.

But, “peak soil” is another matter; topsoil is disappearing and there’s nothing to replace it.

 

Making Soil is a Slow Process

Creating soil is a very slow process. It starts with sand, grit, river silt, and some space dust that lands on Earth. A few hardy plants get a toehold in this crumbled matter; when they die they add vegetable matter. Animal excrement and decaying dead bodies add more nutrients to pump up the richness and fertility of soil.

 

Writing for the Peak Generation blog (May 12, 2010) Matthew Wild points out “It takes tens of thousands of years to make 15 centimetres of topsoil, about six inches’ worth.”

 

Farming Disturbs Soil Ecology

Protected by tree cover, tough prairie-type grasses, or other native vegetation, the world’s topsoil was largely  undisturbed and stable for millions of years. Then, humans developed agriculture and the land was cleared from crops.

 

When there was only a few million people on the planet there was plenty of soil to meet all needs. But, industrial farming and logging has exposed soil to water and wind erosion and the some land is turning into desert; a process, called desertification, that is accelerating with global warming.

 

The pressure on soils has reached the point to where, writes Wild, “The world is losing soil 10 to 20 times faster than it is replenishing it.”

 

More Mouths to Feed from Less Land

At the same time, the world’s population continues to grow, with the United Nations saying we can expect a global population of 9.3 billion in 2050; that’s up from 6.8 billion today.

 

In a May/June 2010 article in Mother Jones writer Julia Whitty quotes David Montgomery, the author of the 2007 book Dirt: The Erosion of Civilizations: “Just when we need more soil to feed the 10 billion people of the future, we’ll actually have less—only a quarter of an acre of cropland per person in 2050, versus the half-acre we use today on the most efficient farms.”

 

The Hope of the Green Revolution

The American agronomist Norman Borlaug (above centre in an experimental rice paddy) was showered with honours, including the 1970 Nobel Peace Prize, for his work in what came to be called The Green Revolution. During the 1960s and later, his developments promised to free the world’s poorest people from starvation.

 

In developing countries such as Mexico, India, and  Pakistan, Borlaug brought in, as an obituary recorded after his death in September 2009, “a combination of modern agricultural production techniques and his new high-yield wheat varieties.

 

“As a result, Mexico became a net exporter of wheat by 1963. Between 1965 and 1970, wheat yields nearly doubled in Pakistan and India, greatly improving the food security in the subcontinent.”

 

Other Resource Shortages Undermine Farming

However, The Green Revolution made extensive use of hydrocarbon and chemical inputs in the form of artificial pesticides, herbicides, and fertilizers. The system also needed a lot of irrigation.

 

But, world supplies of  the chemicals, many of which are derived from crude oil, are running out and getting expensive. And, water for agricultural use is becoming seriously depleted as more and more demands are put on it.

 

Recognizing this problem, scientists are working on ways of creating new soil. According to the article “Scientists Focus on Making Better Soil to Help with Food Concerns,” by Drake Bennett (New York Times, April 29, 2008) “Scientists in Australia and the United States have started making rich new earth from industrial waste, and research into the astonishing fertility of a mysterious Amazonian soil may lead to an additive that can boost the power of soil for thousands of years.”

 

Image Credit

International Rice Research Institute

 

Sources

“Peake Soil: It’s Like Peak Oil only Worse.” Matthew Wild, Peak Generation, May 12, 2010.

“The Last Taboo.” Julia Whitty, Mother Jones, May/June 2010.

“Scientists Focus on Making Better Soil to Help with Food Concerns.” Drake Bennett, New York Times, April 29, 2008.

 

© Canada and the World, July 2010

All rights reserved

 

 

 

Al Ianni

According to Green Facts “Some 10 to 20% of drylands are already degraded, and ongoing desertification threatens the world’s poorest populations and the prospects of poverty reduction.”

 

Adds Julia Whitty in Mother Jones, “In India, the problem of peak soil is already acute. Nearly a quarter of its lands, more than 314,000 square miles, are desert or in the process of becoming desert, according to a recent Indian government report. Desertification will double India's current water usage by 2030...”

 

 

The UN’s Global Environment Outlook in 2007 said that by 2025, about 1.8 billion people will be living in countries or regions with absolute water scarcity; two-thirds of the world’s population could be living in areas under “water stress.”