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  • From: "TradingPostPaul" <tradingpost@riseup.net>
  • To: livingontheland@lists.ibiblio.org
  • Subject: [Livingontheland] LOSING SOIL
  • Date: Wed, 04 Jul 2007 20:45:15 -0600


Earth Policy Institute
Plan B 2.0 Book Byte
For Immediate Release
June 27, 2007

Whether the land is in northern Syria, Lesotho, or elsewhere, the health of
the people living on it cannot be separated from the health of the land
itself.

LOSING SOIL

http://www.earth-policy.org/Books/Seg/PB2ch05_ss3.htm

Lester R. Brown

In 1938, Walter Lowdermilk, a senior official in the Soil Conservation
Service
of the U.S. Department of Agriculture, traveled abroad to look at lands
that
had been cultivated for thousands of years, seeking to learn how these
older
civilizations had coped with soil erosion. He found that some had managed
their land well, maintaining its fertility over long stretches of history,
and
were thriving. Others had failed to do so and left only remnants of their
illustrious pasts.

In a section of his report entitled The Hundred Dead Cities, he described a
site in northern Syria, near Aleppo, where ancient buildings were still
standing in stark isolated relief, but they were on bare rock. During the
seventh century, the thriving region had been invaded, initially by a
Persian
army and later by nomads out of the Arabian Desert. In the process, soil
and
water conservation practices used for centuries were abandoned. Lowdermilk
noted, Here erosion had done its worst....if the soils had remained, even
though the cities were destroyed and the populations dispersed, the area
might
be re-peopled again and the cities rebuilt, but now that the soils are
gone,
all is gone.

Now fast forward to a trip in 2002 by a United Nations team to assess the
food
situation in Lesotho, a small country of 2 million people imbedded within
South Africa. Their finding was straightforward: Agriculture in Lesotho
faces
a catastrophic future; crop production is declining and could cease
altogether
over large tracts of the country if steps are not taken to reverse soil
erosion, degradation, and the decline in soil fertility. Michael Grunwald
reports in the Washington Post that nearly half of the children under five
in
Lesotho are stunted physically. Many, he says, are too weak to walk to
school.

Whether the land is in northern Syria, Lesotho, or elsewhere, the health of
the people living on it cannot be separated from the health of the land
itself. A large share of the worlds 852 million hungry people live on land
with soils worn thin by erosion.

The thin layer of topsoil that covers the planets land surface is the
foundation of civilization. This soil, measured in inches over much of the
earth, was formed over long stretches of geological time as new soil
formation
exceeded the natural rate of erosion. As soil accumulated over the eons, it
provided a medium in which plants could grow. In turn, plants protect the
soil
from erosion. Human activity is disrupting this relationship.

Sometime within the last century, soil erosion began to exceed new soil
formation in large areas. Perhaps a third or more of all cropland is losing
topsoil faster than new soil is forming, thereby reducing the lands
inherent
productivity. Today the foundation of civilization is crumbling. The seeds
of
collapse of some early civilizations, such as the Mayans, may have
originated
in soil erosion that undermined the food supply.

The accelerating soil erosion over the last century can be seen in the dust
bowls that form as vegetation is destroyed and wind erosion soars out of
control. Among those that stand out are the Dust Bowl in the U.S. Great
Plains
during the 1930s, the dust bowls in the Soviet Virgin Lands in the 1960s,
the
huge one that is forming today in northwest China, and the one taking shape
in
the Sahelian region of Africa. Each of these is associated with a familiar
pattern of overgrazing, deforestation, and agricultural expansion onto
marginal land, followed by retrenchment as the soil begins to disappear.

Twentieth-century population growth pushed agriculture onto highly
vulnerable
land in many countries. The overplowing of the U.S. Great Plains during the
late nineteenth and early twentieth centuries, for example, led to the
1930s
Dust Bowl. This was a tragic era in U.S. history, one that forced hundreds
of
thousands of farm families to leave the Great Plains. Many migrated to
California in search of a new life, a move immortalized in John Steinbecks
"The Grapes of Wrath."

Three decades later, history repeated itself in the Soviet Union. The
Virgin
Lands Project between 1954 and 1960 centered on plowing an area of
grassland
for wheat that was larger than the wheatland in Canada and Australia
combined.
Initially this resulted in an impressive expansion in Soviet grain
production,
but the success was short-lived as a dust bowl developed there as well.

Kazakhstan, at the center of this Virgin Lands Project, saw its grainland
area
peak at just over 25 million hectares (44 millions acres) around
1980, then shrink to 14 million hectares today. Even on the remaining land,
however, the average wheat yield is scarcely 1 ton per hectare, a far cry
from
the nearly 8 tons per hectare that farmers get in France, Western Europes
leading wheat producer.

A similar situation exists in Mongolia, where over the last 20 years half
the
wheatland has been abandoned and wheat yields have also fallen by half,
shrinking the harvest by three fourths. Mongolia--a country almost three
times
the size of France with a population of 2.6 million--is now forced to
import
nearly 60 percent of its wheat.

Dust storms originating in the new dust bowls are now faithfully recorded
in
satellite images. In early January 2005, the National Aeronautics and Space
Administration (NASA) released images of a vast dust storm moving westward
out
of central Africa. This vast cloud of tan-colored dust stretched over some
5,300 kilometers (roughly 3,300 miles). NASA noted that if the storm were
relocated to the United States, it would cover the country and extend into
the
oceans on both coasts.

Andrew Goudie, Professor of Geography at Oxford University, reports that
Saharan dust storms--once rare--are now commonplace. He estimates they have
increased 10-fold during the last half-century. Among the countries in the
region most affected by topsoil loss from wind erosion are Niger, Chad,
Mauritania, northern Nigeria, and Burkino Faso. In Mauritania, in Africas
far
west, the number of dust storms jumped from 2 a year in the early 1960s to
80
a year today.

The Bodili Depression in Chad is the source of an estimated 1.3 billion
tons
of wind-borne soil a year, up 10-fold from 1947 when measurements began.
The 2
to 3 billion tons of fine soil particles that leave Africa each year in
dust
storms are slowly draining the continent of its fertility and, hence, its
biological productivity. In addition, dust storms leaving Africa travel
westward across the Atlantic, depositing so much dust in the Caribbean that
they cloud the water and damage coral reefs there.

In China, plowing excesses became common in several provinces as
agriculture
pushed northward and westward into the pastoral zone between 1987 and 1996.
In
Inner Mongolia (Nei Monggol), for example, the cultivated area increased by
1.1 million hectares, or 22 percent, during this period. Other provinces
that
expanded their cultivated area by 3 percent or more during this nine-year
span
include Heilongjiang, Hunan, Tibet (Xizang), Qinghai, and Xinjiang. Severe
wind erosion of soil on this newly plowed land made it clear that its only
sustainable use was controlled grazing. As a result, Chinese agriculture is
now engaged in a strategic withdrawal in these provinces, pulling back to
land
that can sustain crop production.

Water erosion also takes a toll on soils. This can be seen in the silting
of
reservoirs and in muddy, silt-laden rivers flowing into the sea. Pakistans
two large reservoirs, Mangla and Tarbela, which store Indus River water for
the countrys vast irrigation network, are losing roughly 1 percent of their
storage capacity each year as they fill with silt from deforested
watersheds.

Ethiopia, a mountainous country with highly erodible soils on steeply
sloping
land, is losing an estimated 1 billion tons of topsoil a year, washed away
by
rain. This is one reason Ethiopia always seems to be on the verge of
famine,
never able to accumulate enough grain reserves to provide a meaningful
measure
of food security.

Fortunately there are ways to conserve and rebuild soils. These will be
discussed in the next Earth Policy Institute Book Byte.

[SK: Brown would agree that continual population growth will overwhelm
remediation. He has written that elsewhere & recently.]

# # #

Adapted from Chapter 5, Natural Systems Under Stress, in Lester R.
Brown, Plan B 2.0: Rescuing a Planet Under Stress and a Civilization in
Trouble (New York: W.W. Norton & Company, 2006), available on-line at
www.earthpolicy.org/Books/PB2/index.htm

Additional data and information sources at www.earthpolicy.org

For information contact:

Media Contact:
Reah Janise Kauffman
Tel: (202) 496-9290 x 12
E-mail: rjk@earthpolicy.org





  • [Livingontheland] LOSING SOIL, TradingPostPaul, 07/04/2007

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