Dirt: The Erosion of Civilizations - Kootenay Local Agricultural Society

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may prove our best hope for maintaining food production in the face of
population growth and continuing loss of agricultural land. In principle,
intensive organic methods could even replace fertilizer-intensive agriculture
once cheap fossil fuels are history.
Here is the crux of Wes Jackson’s argument that tilling the soil has been
an ecological catastrophe. A genetics professor before he resigned to become
president of the Land Institute in Salina, Kansas, Jackson says he is not
advocating a return to the bow and arrow. He just questions the view that
plowing the soil is irrefutably wholesome, pointedly suggesting that the
plow destroyed more options for future generations than did the sword and
that—with rare exceptions—plow-based agriculture hasn’t proven sustainable.
He estimates that in the next two decades severe soil erosion will
destroy 20 percent of the natural agricultural potential of our planet to grow
crops without fertilizer or irrigation.
Yet Jackson is neither doomsayer nor Luddite. In person he sounds more
like a farmer than an environmental extremist. Instead of despair, he calls
for agricultural methods based on emulating natural systems rather than
controlling, or replacing them. In promoting natural systems agriculture,
Jackson is the latest prophet for Xenophon’s philosophy of adapting agriculture
to the land rather than vice versa.
Drawing on experience in the American farm belt, Jackson seeks to
develop an agricultural system based on imitating native prairie ecosystems.
Unlike annual crops raised on bare, plowed ground, the roots of
native perennials hold the soil together through drenching rainstorms.
Native prairies contain both warm-season and cold-season grasses, as well
as legumes and composites. Some of the plants do better in wet years, some
thrive in dry years. The combination helps keep out weeds and invasive
species because plants cover the ground all year—just like our eco-lawn.
As ecologists know, diversity conveys resilience—and resilience, Jackson
says, can help keep agriculture sustainable. Hence he advocates growing a
combination of crops year-round to shield the ground from the rain’s erosive
impact. Monocultures generally leave the ground bare in the spring,
exposing vulnerable soil to erosion for months before crops get big enough
to block incoming rain. Storms hitting before crops leaf out cause two to
ten times the erosion of storms later in the year when the ground lies
shielded beneath crops. Under monoculture, one good storm at the wrong
time can send erosion racing decades ahead of soil production.
The beneficial effects of Jackson’s system are evident at the Land Institute.
Research there has shown that a perennial polyculture can manage
dirty business