Sustainable Farming

This is a bit late, but in case you haven't read it, the September 2008 issue of National Geographic has a very interesting feature story about soils around the world, the rapid degradation we're causing, and the efforts around the world to improve farming that did and didn't work out:

In the first—and still the most comprehensive—study of global soil misuse, scientists at the International Soil Reference and Information Centre (ISRIC) in the Netherlands estimated in 1991 that humankind has degraded more than 7.5 million square miles of land. Our species, in other words, is rapidly trashing an area the size of the United States and Canada combined.
...
Journalists sometimes describe unsexy subjects as MEGO: My eyes glaze over. Alas, soil degradation is the essence of MEGO. Nonetheless, the stakes—and the opportunities—could hardly be higher, says Rattan Lal, a prominent soil scientist at Ohio State University. Researchers and ordinary farmers around the world are finding that even devastated soils can be restored. The payoff, Lal says, is the chance not only to fight hunger but also to attack problems like water scarcity and even global warming. Indeed, some researchers believe that global warming can be slowed significantly by using vast stores of carbon to reengineer the world's bad soils. "Political stability, environmental quality, hunger, and poverty all have the same root," Lal says. "In the long run, the solution to each is restoring the most basic of all resources, the soil."