Dirt: The Erosion of Civilizations - Kootenay Local Agricultural Society

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Estimates for when petroleum production will peak range from before
2020 to about 2040. Since such estimates do not include political or environmental
constraints, some experts believe that the peak in world oil production
is already at hand. Indeed, world demand just rose above world
supply for the first time. Exactly when we run out will depend on the political
evolution of the Middle East, but regardless of the details oil production
is projected to drop to less than 10 percent of current production by
the end of the century. At present, agriculture consumes 30 percent of our
oil use. As supplies dwindle, oil and natural gas will become too valuable
to use for fertilizer production. Petroleum-based industrial agriculture will
end sometime later this century.
Not surprisingly, agribusiness portrays pesticide and fertilizer intensive
agriculture as necessary to feed the world’s poor. Even though almost a billion
people go hungry each day, industrial agriculture may not be the
answer. Over the past five thousand years population kept pace with the
ability to feed people. Simply increasing food production has not worked
so far, and it won’t if population growth keeps up. The UN Food and Agriculture
Organization reports that farmers already grow enough to provide
3,500 calories a day to every person on the planet. Per capita food production
since the 1960s has increased faster than the world’s population.
World hunger persists because of unequal access to food, a social problem
of distribution and economics rather than inadequate agricultural capacity.
One reason for the extent of world hunger is that industrialized agriculture
displaced rural farmers, forcing them to join the urban poor who cannot
afford an adequate diet. In many countries, much of the traditional
farmland was converted from subsistence farms to plantations growing
high-value export crops. Without access to land to grow their own food,
the urban poor all too often lack the money to buy enough food even if it
is available.
The USDA estimates that about half the fertilizer used each year in the
United States simply replaces soil nutrients lost by topsoil erosion. This
puts us in the odd position of consuming fossil fuels—geologically one of
the rarest and most useful resources ever discovered—to provide a substitute
for dirt—the cheapest and most widely available agricultural input
imaginable.
Traditional rotations of grass, clover, or alfalfa were used to replace soil
organic matter lost to continuous cultivation. In temperate regions, half
the soil organic matter commonly disappears after a few decades of plowing.
In tropical soils, such losses can occur in under a decade. By contrast,
dirty business