Beyond dirt, there’s soil—the living, vibrant matrix of organisms in which our food grows. Some experts calculate there are more living organisms beneath the surface of the earth than above it. This rich, dark world of humus is critical to food and life. At a TEDx conference in Manhattan, in January, Fred Kirschenmann, president of Stone Barns Center, cautioned we should not take soil for granted. In fact, we’re losing it at an unprecedented rate, spelling uncertainty for our global food future.
His choice of topic was appropriate for a conference exploring ideas for “Changing the Way We Eat,” for it is only with changes in agricultural practices that we can conserve soil, the most basic building block of our food. TED is a nonprofit devoted to ideas worth spreading, and its conferences bring people together from three worlds: technology, entertainment and design (thus, TED). TEDx is an independently organized TED event.
A theologian, philosopher and farmer, Fred Kirschenmann is a leading voice in the dialogue about the challenges of modern agriculture and the pursuit of sustainable agriculture. And he’s given a lot of thought to the soil that sustains us all.
Fred noted that estimates of the number of microorganisms contained in one teaspoon of living soil range from 50 million to 4 billion. “Without this community of life, we would have no food,” he said. “We’re not going to change the way we eat without supporting soil.”
Soil Loss and Degradation
But today, because of industrial agricultural methods, we’re losing soil at unprecedented rates. In the last half-century, we’ve lost half of the topsoil in the United States. Of the remaining soil on the planet, a quarter of it is degraded; it no longer has the vitality to produce quality food. And we’re losing soil at faster rates now because of severe weather events triggered by climate change. Soil is not a renewable resource. It took the Earth millions of years to make it, and it won’t be easily restored.
While it may be tempting to blame farmers and say they should do a better job at protecting soil, Fred noted that we’ve all been part of creating a food system in which farmers must produce food as cheaply as possible to meet public demand and expectations for cheap food. So they concentrate animals in high numbers and grow monocultures—both of which contribute to soil loss and degradation.
Changing the Way We Farm Can Conserve Soil
But the good news, Fred said, is that there are alternatives. If farmers would move to longer rotations in their crops—away from two-year rotations of corn and beans, to three- and four-year cycles that help feed the soil with nitrogen—then not only could they conserve soil, but they could reduce pesticide and synthetic fertilizer use. Soil scientists find richer, denser, more porous soil with longer rotations.
Other solutions lie in using perennial varieties of crops, such as wheat, rather than annual varieties. Perennials have denser and deeper root systems, are more drought-resistant and help hold soil in place. The planting of winter cover crops can help fix nitrogen in the soil and prevent erosion, and when these crops are ploughed back into the ground at the end of winter, it helps build up the soil.
Permaculture is another evolving agricultural practice that helps conserve and build up soils. In permaculture, farmers garden their land like a living organism, where all plants and animals work in concert in support of each other: turkeys, for example, roaming freely in fields of squash plants eating insects, their droppings enriching the soil. Farmers don’t need to apply insecticides or haul manure out to the fields, and soil is less disturbed.
But How to Bring about Meaningful Change?
The dark side of current agricultural practices will necessitate many of these soil-conserving changes, noted Fred. As we’re drawing down the planet’s oil, phosphorous and rock phosphate necessary to maintain our current agricultural system, these resources will become more expensive—and, consequently, so will food.
On the bright side, a new generation of food advocates, farm-to-table chefs, CSA members and young farmers are paying attention to soil as central to the taste and nutrition they seek in their food. They know soil conservation is key to the food they grow and to the health of the environment. By demanding good food grown well, we can help conserve biologically healthy soil—the lifeline to the future.
Originally published on July 12, 2012