Eliot Coleman suggests that we educate ourselves about this issue at the National Organic Program to allow for "soil-less" organics. He is one of  dozens of elders in the farm world who are concerned about this issue.  Read up on the issue and sign the petition here: Keep the Soil in Organic.org.  There is one petition for consumers and another for growers.

In short:

Hydroponic growing is a soil-less system in which all the nutrients are supplied to the plants through an irrigation system. There is no soil involved. It is ingenious, and it works well, which is why virtually all the conventional greenhouse vegetables are grown this way. But it is NOT organic. There is no reliance on the microbial activity of the soil to provide the biological diversity that is the basis of organic growing. The old adage for organic farming has always been, “Feed the soil, not the plant.” Hydroponic growing is based on the opposite belief, “Feed the plant, not the soil.” We are not arguing with whether either system can be effective. Most of the world's vegetables grown in greenhouses are now grown hydroponically. Only the organic growers are following a different, more difficult path.

The stated NOP standard emphasizes that organic growing is based on caring for the soil, but their refusal to prohibit soil-less growing defies their own standard.