I once found the sight of soil opened up to receive seed so delicious I could imagine tasting it. After all, it looks very much like unfrosted chocolate cake.

But now I know better. It's a food desert.

My son and I drove 10 hours from Portland to San Francisco on the Friday before Easter and then 10 hours back on Monday, almost all of it on I-5. It's a gorgeous ride, sometimes through mountains and mostly through agricultural valleys. I love that peripheral whiz of green growing things while I drive, but everything I've learned about agriculture over the last three years told me that most of the farming alongside the highway was...bad. It's the kind of conventional farming that contributes to global warming and disrupts the ancient partnership between plants and soil microorganisms.

How long ago was this field tilled? Possibly as far back as fall, perhaps only a few weeks before I drove by. In any case, the carbon dioxide removed from the air by plants through photosynthesis, then converted into carbon fuel for the plants' growth, then shared with the soil microorganisms -- 6 billion in a tablespoon of soil! -- in exchange for minerals, and then fixed in the soil as carbon by the microorganisms-- THAT carbon was released back into the atmosphere by tilling, where it joins the rest of the CO2 heating our planet. The longer the soil is open to the elements, the more soil carbon wafts away as CO2. In fact, a large portion of the excess CO2 in our atmosphere comes from millennia of ripping open the soil for agriculture.

Why did I say a food desert, when people usually use that term to describe inner city areas bereft of places where residents can buy food? Because landscapes where all the plants have been removed are a food desert for the microorganisms. They depend on plants for their food -- their carbon meal -- and can't do their work on behalf of our planet without it. They can't build tiny structures in the soil to hold precious water, they can't break down toxic materials dumped on the soil, they can't deliver nutrients to plants.

I've always walked around outside with my head down-- an old habit that came from searching out arrowheads and cool rocks. Now I look at plant cover wherever I walk, happy when I see land bristling with a variety of plants, sighing at the food deserts. Including the bare spots on my own lawn!