Is Coal Ash in Soil a Good Idea?

(Scientific American 2-6-09) Crops across the country are grown in soil amended with coal fly ash—the same substance that caused a massive environmental emergency in December when it gushed from a holding pond at a Tennessee power plant. Tons of fly ash are routinely added to soil to nourish vegetables, peanuts and other crops, primarily in the Midwest and Southeast. But now the spill has raised questions about whether this longstanding agricultural practice is environmentally sound.