Subsoiling (very deep "plowing")

I am in NW Pennsylvania, a little south of Erie and I have been researching my soil. My yard is very flat. Wile I initially thought that my soil was filled with clay and very compancted, what I am finding in my research is that my soild structure was created when the glaciers came through. There is a layer from 7-17 inches that is what they call till/loam with a decent amount of structure that has a little size to it (definitely not sandy). Under that is something that they call fragipan. What is happening in my area is that the water table tends to be quite high (in wet season they say from 6-18 inches below the surface) and it sort of sits on top of the fragipan in the wetter time of year. The fragipan layer makes it very difficult for the water to percolate through.

I am trying to figure out if subsoiling (sort of like plowing, but a lot deeper) would make sense in an urban setting and would be of any benefit to break up the tough fragipan layer and allow the roots of trees like fruit trees to better permeate it. From what I have read so far, it appears that the roots of trees tend to take a sideways path once they get to the fragipan layer unless they find a crack in the fragipan that they can grow down through. My only concern about subsoiling is that some people have said that the ground will eventully revert back to what it started as unless A LOT of compost and other natural materials is continually added. I would like to develop a food forest/permaculture site, so that would not really be a problem since part of the idea is to continually ammend the soil.

I guess I wonder if subsoiling would work long enough to get fruit trees well established in the fragipan (dense/brittle/non-permeable) layer and, if they do become well established, if they would then help the overall drainage of the site since that layer would be "broken open", so to speak. One of the early on challenges would be to make sure that the fruit trees have enough initial drainage when planted so as to not rot the root system when the weather is wet.

Any comments or suggestions would be appreciated.

In an urban/suburban setting? NO!!! Not because it won't work (it should) but because it works really well at cutting power lines, fiber, phone, water, gas, etc.

Call the locator company, get all the lines marked, then do a drill/drive method to fracture that fragipan around the trees. You can dig a posthole to the pan, then use a hammer drill. Or you can use a tamper/root/rock prybar like this http://www.lowes.com/pd_277887-42268-BAP-175-LW+33375_0__?productId=3055439

Subsoiling works, the beauty is it does surprisingly little damage to the upper layer structures and life. But it is an EXTREMELY power intensive job.

I am actually not concerned about the utilities portion, because they are at the front of my property and where I am proposing the possibility of subsoiling is in my back yard. My back yard and all the neighbors back yards butt up to each other and the utilities run along the street at the fronts of our properties.

I looked up the link. Reminds me of a spud bar (as my dad calls it) that my dad has. It is about 6 foot long and I would guess 1.5" diameter steel. Hefty little bugger.

How long would the subsoiling last if done? Does it matter the method for the length of time it lasts?