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Dec 19, 2012

Midwest Soils Losing Ground 5-100 ton per acre per year!


EnvironmentalWG


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Bad federal policy and intensifying storms are washing away the rich dark soils in the Midwest that made this country an agricultural powerhouse and that remain the essential foundation of a healthy and sustainable food system in the future. The Environmental Working Group produced this short film with Atlas Films that provides stark images illustrating how federal farm subsidies and ethanol mandates, piled on top of skyrocketing crop prices are supporting an intensive monoculture that kneecaps any hope for a more resilient and diverse food and farm system. Go to www.ewg.org/losingground/ for more information.


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Above: Grass waterways, filter strips, and vegetative
buffers help hold soil in place and protect
northwest Iowa’s Ocheyedan River.


Above: Iowa State University soil scientist Rick
Cruse says current levels of soil erosion are unsustainable.
“We are losing ground,” he says.

A closer look. “We are losing
ground,” says Iowa State soil scientist
Rick Cruse. “Soil is eroding faster
than new soil is forming. We have
data to show that we are continuing
to degrade the soil resource. The only
way that we can maintain high productivity
is to keep soil in place.”
Cruse teamed up with John Laflen,
a retired USDA Agricultural Research
Service agricultural engineer, to create
IDEP, hoping to bring increased
attention to the problem of excessive
soil erosion. This daily simulation of
the erosion process on nearly 20,000
hillslopes across the state was implemented
with the help of a long list of
partner organizations.
“It’s not average rainfall that drives
soil erosion rates,” Cruse explains. “It
is the intense storms. We combine a
number of technologies to allow us
to project erosion based on local data
and soil conditions, not averages.”
He also has concerns about whether
T levels, defined as the maximum rate
of annual soil loss that will permit
crop productivity to be sustained economically
and indefinitely on a given
soil, truly are sustainable.
T time. On Clarion-Nicollet-Webster
soils that are typical for much of
the state, the T rate is considered to be
around 5 tons per acre per year. But
Cruse says recent studies show “solid
evidence” that soil formation is considerably
less, perhaps only about 0.25
tons annually.
“There is an increasing
amount of evidence that even the ‘acceptable’
rate is higher than the rate
that soil is forming,” he says. “And 
with the trend toward more frequent
heavy rainfall events, along with
more fragile land being brought into
production, we’re likely to see accelerated
levels of soil erosion.”

Related Links: 
Deere Furrow Magazine_Feb 2012 - "Losing Ground" Article - page 22-24
Losing ground-executive-summary
Excellent Articles!  Monte

Other related Links:

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