“By the time I started writing I was in such a state of grief that the only thing that sustained me was that I could go outside and just lie facedown on the earth,” said Alice Walker, describing in a talk in San Francisco how she survived the trauma of writing Possessing the Secret of Joy, a book about genital mutilation in Africa. “Somehow I got the energy that I always get from the earth directly….It gives me everything, including peace of mind. Just by being underneath my feet, just by lying on it.”

I could use some peace of mind these days, but I can’t find a comfortable plot of earth to lie down on. There’s grass growing on the parkway beside the building where I live, but relaxing there isn’t an appealing prospect: it’s such a narrow swath my hands would hit the curb and sidewalk, and the high dog-shit factor is daunting. I could walk a few blocks south and lie down on the earth in Wicker Park, but it’s surrounded by houses and people. Humboldt Park has plenty of peaceful spots to rejuvenate the spirit, but I’d probably be rolled like a bum or worse.

Not only do I not have a place to press my body against the earth, but these days I rarely touch it at all. Last fall I tried to keep track of how often I walked on the ground. Not on concrete, asphalt, gravel, carpeting, or the boards of someone’s backyard deck, but on real live dirt. I kept a log in a small notebook I was carrying around at the time, which I ran across the other day. On three lines I had written, “10/2 shortcut across park, 45 seconds; 10/4 walked beside bike path, 5 min; 10/12 vacant lot, 15 seconds.” That’s all I’d recorded. I’ve walked on grass since October, but the amount of time was so negligible I forgot to record it.

This lack of direct contact with the earth bothers me. I have plenty of other things to worry about–old standbys like death and desperation, and new things like the Contract With the American Family. So I don’t want to say that all that concerns me is planning for the next time I can put my toes in the dirt. But there’s something alienating about always having a slab of concrete between me and the earth.

The difference between soil and concrete is the difference between life and death. Soil writhes with living organisms: A single gram– an amount that wouldn’t even fill your cupped palm–holds at least 1,000,000 bacteria, 1,000 algae, 1,000 protozoa, and anywhere from 10,000 to 100,000 actinomycetes, an organism that’s sort of a cross between algae and bacteria. I asked Bob Darmody, a scientist from the University of Illinois whose expertise is in soils, how many different species of these microorganisms would be living in Illinois earth. He laughed like I was nuts. “A tremendous number,” he said. “Soil is one of the most dynamic ecosystems in the world. It’s incredibly diverse.”

Yeah, but how many? Could he send me a list? Apparently this was a little like asking if he could fax me a list of the plants and animals that live in the western hemisphere. The variety of species is so immense that scientists don’t even come close to knowing what they all are.

This time of year, all you have to do is smell a handful of soil to understand that it’s alive. Aside from the microorganisms, the top few inches of the earth teem with nematodes, earthworms, springtails, mites, ants, millipedes, centipedes, daddy longlegs, pill bugs, and the larvae of flies, beetles, and moths. They’re all busy hatching, metamorphosing, searching for mates, coupling, reproducing, struggling against predators, finding food, passing wastes, and eventually dying. Then there’s the richness of plant life–roots shoving through the humus, seeds sprouting, mushrooms springing up, algae colonizing cracks in rocks. All these struggles generate the scent of life.

A soil ecosystem has an edge effect, just as other ecosystems do: its greatest richness occurs close to the point where the dirt meets the air, in the top few inches of soil. This is where the most oxygen is and, in the summer, where the greatest warmth and food supply are. There are types of bacteria that live deep in the earth, but they become much less numerous as the habitat becomes less hospitable.

Concrete isn’t like this. Impermeable and inert, dull and stupid, it grows harder over time. The ancient Romans invented this conglomerate, and some of what they mixed and laid is still intact. It’s too dense for oxygen atoms to float around in, and it’s so caustic nothing can survive. Not even a fungus can live in it. “There’s a remote chance that there might be a bacteria that could survive in a dormant state in concrete,” Bob Darmody said. But nothing that’s carrying out the processes of life.

Last week I interviewed someone at the Chicago Academy of Sciences in Lincoln Park. I was dressed up in a skirt and blouse and jacket, but after I walked out of the museum I went into the park to lie down in the grass. It was now or never–or at least not for a long time. I spread my jacket out in a jagged patch of sunlight edged by the shade of two maples and lay back.

How much of the joy of lying in the sun is about the warmth from above, and how much is about the solid feel of a whole planet beneath one’s body? The gravity gripped me tightly to the planet. Every inch of my back, the backs of my legs, arms, neck, and head were snug against the earth. I imagined the stirring of the soil ecosystem underneath me, alive and breathing. I pictured as best I could the battles and triumphs and failures of millions of organisms too tiny to see.

When I opened my eyes I was lying in shade. I’d lain there long enough that the earth had turned, with the soil and me along for the ride.