The joy of dirt

Soil is as essential a natural resource as air and water. If you don’t already know the bad news, we’re running out of soil. As with other prominent resources that have accumulated over millions of years, we, the people of planet Earth, have been churning through the stuff that feeds us since the first Neolithic farmer broke the ground with his crude plow. The rate varies, the methods vary, but the results are eventually the same. Books like Jared Diamond’s Collapse and David Montgomery’s Dirt: The Erosion of Civilizations lay out in painful detail the historic connections between soil depletion and the demise of those societies that undermined the ground beneath their feet.

In the hyper-abstracted economics of today, it is easy to forget that land is one of the irreducible foundations of all economies. As the world economy has deflated in the last year, it has driven many people all over the world back to earth, if only to grow a few tomatoes in their backyards. In 2009, the Associated Press reported a 19 percent increase in residential seed sales in the U.S., a bump known in the business as “recession gardening.” When the Obamas planted a garden on the White House lawn, it was at once an economic, environmental and spiritual gesture—a nod, if nothing else, to the primacy of dirt.

With this in mind, I made the pilgrimage up from San Francisco to sit at the feet of John Jeavons, who has probably spent as much of his life thinking about building soil as anyone who has ever lived. Jeavons started his career in the 1960s as a systems analyst at Stanford University. When the spirit moved him to pursue agriculture as a vocation, he brought that kind of analytical thinking with him. These are the questions that drove him: How many calories does a person need to survive? What is the smallest plot of land needed to grow those calories for one person for one year? How much land do we need to feed all the people on the planet? read the article...