Healthy soil and sustainable growing

["TradingPostPaul" <tradingpost@riseup.net>]

from Eating Fossil Fuels
by Dale Allen Pfeiffer

Modern intensive agriculture is unsustainable. Technologically enhanced
agriculture has augmented soil erosion, polluted and overdrawn groundwater
and surface water, and even (largely due to increased pesticide use) caused
serious public health and environmental problems. Soil erosion, overtaxed
cropland and water resource overdraft in turn lead to even greater use of
fossil fuels and hydrocarbon products. More hydrocarbon based fertilizers
must be applied, along with more pesticides; irrigation water requires more
energy to pump; and fossil fuels are used to process polluted water.

It takes 500 years to replace 1 inch of topsoil.21 In a natural
environment, topsoil is built up by decaying plant matter and weathering
rock, and it is protected from erosion by growing plants. In soil made
susceptible by agriculture, erosion is reducing productivity up to 65% each
year.22 Former prairie lands, which constitute the bread basket of the
United States, have lost one half of their topsoil after farming for about
100 years. This soil is eroding 30 times faster than the natural formation
rate.23 Food crops are much hungrier than the natural grasses which once
covered the Great Plains. As a result, the remaining topsoil is
increasingly depleted of nutrients. Soil erosion and mineral depletion
removes about $20 billion worth of plant nutrients from U.S. agricultural
soils every year.24 Much of the soil in the Great Plains is little more
than a sponge into which we must pour hydrocarbon-based fertilizers in
order to produce crops.

Every year in the U.S., more than 2 million acres of cropland are lost to
erosion, salinization and water logging. On top of this, urbanization, road
building and industry claim another 1 million acres annually from
farmland.24 Approximately three-quarters of the land area in the United
States is devoted to agriculture and commercial forestry.25 The expanding
human population is putting increasing pressure on land availability.
Incidentally, only a small portion of U.S. land area remains available for
the solar energy technologies necessary to support a solar energy-based
economy. The land area for harvesting biomass is likewise limited. For this
reason, the development of solar energy or biomass must be at the expense
of agriculture.

Modern agriculture also places a strain on our water resources. Agriculture
consumes fully 85% of all U.S. freshwater resources.26 Overdraft is
occurring from many surface water resources, especially in the west and
south. The typical example is the Colorado River, which is diverted to a
trickle by the time it reaches the Pacific. Yet surface water only supplies
60% of the water used in irrigation. The remainder, and in some places the
majority of water for irrigation, comes from ground water aquifers. Ground
water is recharged slowly by the percolation of rainwater through the
earth’s crust. Less than 0.1% of the stored ground water mined annually
is replaced by rainfall.27 The great Ogallala aquifer which supplies
agriculture, industry and home use in much of the southern and central
plains states has an annual overdraft up to 160% above its recharge rate.
The Ogallala aquifer will become unproductive in a matter of decades.28

We can illustrate the demand which modern agriculture places on water
resources by looking at a farmland producing corn. A corn crop that
produces 118 bushels/acre/year requires more than 500,000 gallons/acre of
water during the growing season. The production of 1 pound of maize
requires 1,400 pounds (or 175 gallons) of water.29 Unless something is done
to lower these consumption rates, modern agriculture will help to propel
the United States into a water crisis.

In the last two decades, the use of hydrocarbon-based pesticides in the
U.S. has increased 33-fold, yet each year we lose more crops to pests.30
This is the result of the abandonment of traditional crop rotation
practices. Nearly 50% of U.S. corn land is grown continuously as a
monoculture.31 This results in an increase in corn pests which in turn
requires the use of more pesticides. Pesticide use on corn crops had
increased 1,000-fold even before the introduction of genetically
engineered, pesticide resistant corn. However, corn losses have still risen
4-fold.32

Modern intensive agriculture is unsustainable. It is damaging the land,
draining water supplies and polluting the environment. And all of this
requires more and more fossil fuel input to pump irrigation water, to
replace nutrients, to provide pest protection, to remediate the environment
and simply to hold crop production at a constant. Yet this necessary fossil
fuel input is going to crash headlong into declining fossil fuel
production.

see entire article
http://www.fromthewilderness.com/free/ww3/100303_eating_oil.html
Dale Allen Pfeiffer is a geologist from Michigan, U.S. who has been
investigating and writing about Hubbert Peak theory and the specter of
resource wars.  He is the author of the 2003 book Giants in Their Steps and
The End Of The Oil Age in 2004. He has written articles regarding energy at
>From the Wilderness. He is the author of the often cited essay on peak oil
and food production titled Eating Fossil Fuels.