Locavore leaders such as Alice Waters, Michael Pollan, and Barbara Kingsolver all speak of the need for sweeping changes in how we get our food. A longtime leader of this movement is Wes Jackson, who for decades has taken it upon himself to speak for the land, to speak for the soil itself. Here, he offers a manifesto toward a conceptual revolution: Jackson asks us to look to natural ecosystems--or, if one prefers, nature in general--as the measure...