When someone says "dirt", I associate the word with soil, the basic stuff of food and biodiversity. I also think of the way we often treat this ground we walk upon, and each other, that is to say, like dirt, in contrast to what dirt (and our fellow humans) might be, that is, something we celebrate. It is amazing that we seem to have lost respect for this critical part of our existence and may be dooming ourselves and others to poverty if we continue to do so.

As soil--the humus and clay and the minerals and microbes that define the earth's thin living skin--it is literally at the root of most everything we do and eat. It is a good lesson in humility to learn something about it, and to learn that for our utter dependence on soil we hardly understand it and we may never be able to. A fun and remarkable resource on this subject emerged in my research, the recent book, Dirt, by William Bryant Logan.

It appears that the earth is made of dust built up from old stars. Billions of years ago, this stardust was molten and over time it formed a crust and oceans and atmosphere. Life evolved in the oceans, and as some of the primordial lifeforms were carried onto land they excreted organic acids which combined with the carbonic acids of rainfall to form the first soils. Later, the cyanobacteria, or blue-green algae, began photosynthesis and released oxygen into the atmosphere, helping a number of emerging lifeforms gain a hold on the surface of the earth. After eons, lifeforms have evolved, lived, died and decomposed, and the earth's surface has become a wondrous skin, a system that recycles organic matter, cycles nutrients, and links everything terrestrial into the massive web of systems that we call life.

We actually know very little about how soil works. We know that no two molecules of humus, the dark organic matter of soils, are the same, though they share similar properties, such as a carbon to nitrogen ratio (10:1). We can see basic soil structure and know when it is not healthy. We are beginning to understand some of the organisms living in soil that through complex relationships help plants obtain nutrients and depend on plants for sugars and other nutrients. Beyond this important basic knowledge, we are mostly just learning to be aware of how valuable soil is. Historic agriculture has tended to deplete soil fertility. Entire cultures have been shown to have collapsed because of soil loss. We certainly hope to learn from their lessons. We are making progress and have slowed the rate of topsoil loss nationally, though a basic trend still suggests that three to six billion tons is lost in the US annually to human activity, at a rate about three times faster than it is rebuilt, and for every pound of food, 22 pounds of agricultural soil is lost to erosion. Most farmers in our area are constantly improving their practices to assist soil conservation and soil building, but the task compared to increasing demand for food and agricultural products is not easy. One small suggestion for around the house is to compost yard debris and kitchen waste. (Call the Ecology Center or the UC Master Gardener program, 527-2608, for a compost brochure or assistance.)

Especially in a community that values its agricultural heritage and has an economy that to large degree is based on agriculture, soil is part of our lives. We should do all we can to help conserve it, nurture it, celebrate it, and yes, stop treating it like dirt.