Gary, hydrophonics may be the way to go. Here's an offbeat approach:
http://www.growingedge.com/community/ar ... =yes&q=753
I'm in the process of running the pond water from my koi pond down the hill and into a trench where we are growing vegetables, pachysandra and rhodos. First year results were amazingly good -- I only screwed up by not making my surge basin large enough and washing out the down hill side.
What I would do, is run the tap root down a foot or so in the trench, then turn it 90 degrees and let it grow laterally. If you keep the trench moist enough, and if you keep moving the growing end up and into the trench, I think it would work fine. This approach would actually work better if the grape plants were already established. I dug up a wild grape plant this afternoon in our woods, and although the tap root was more than three feet long, I was able to easily make it bend and run at a 90 degree angle at the one foot depth.
You know, the grape plant wants and grows a long tap root, but I don't think it has to go down, just be long. It's very easy to train grape vines -- grape roots must be just as easy to train. [I think.]
I'll play with this wild plant this summer and see if it survives -- I'll bet your daughter would love to help you solve this problem and although I'm always overly optomistic with hairbrained ideas, this one might actually work.
Let me know what you think.