I would say yes, If you get 5-6 feet of soil that would be enough provided the water gets down there.
Some ideas:
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Here is a discussion of Caliche.
https://permies.com/t/74432/Sunken-beds-hardpan-caliche
Vinegar apparently dissolves Caliche, if you dig down to that level. Not sure much you need, but I would assume a lot. Drill some hole in the caliche and and fill them with vinegar to erode the imperiable layer. -----------------------------------------------------------------------
If you decide to use a dozer try to maintain your soil horizons. Move off the Clay, Break up the caliche, maybe spray it with some vinegar to dissolve it a bit, put it back, cover it back up, build your new topsoil with old or ruined straw of hay, manure, plant first year buckwheat or besseme clover and till it under.
See if Augie has any thoughts. He has experience with farming and heavy equipment operation.
--------------------------------------------------------- Plant on top of the soil in straw bales. Might be temporary solution that would leave a good pile of staw to help create humus.
https://www.organicgardener.com.au/blogs/how-make-straw-bale-gardens
https://gardeningvlogs.com/tag/straw-bale-gardening-australia/
I have not viewed either of these, but California and Australia are dry and have hard soils and this is one of ignoring the hard pan and planting above it.
Good Luck with your raised beds!
On an agricultural scale, hardpan is commonly tempered by breaking it up with a sub-soiler or chisel plow. A class-one compact tractor can handle a single-shank ripper in most soils. You might have to make multiple passes depending on how tightly the pan is packed, moisture content, rock, etc. The depth you’re able to go will greatly depend on the size of machine that you’re using.
If I was faced with shallow, rocky, clay soils I would skip the whole exercise and go straight to raised beds. Set up the boxes - 18”-24” deep, fill them with good topsoil and plenty of well-rotted compost, and not think about hardpan ever again.
My garden is 100% a raised bed so I’ve not had a real need to break up the pan there. I try to do at least one row double-dig/compost every year. Haven’t done that lately because I let myself run low on stable waste. Now that I’ve replenished my poo pile I’ll get that program back on track.
Once you’ve broken the pan and incorporated a good portion of compost into the top 12” of soil the battle is half won. At that point simply adding compost every year should keep your soils in good condition.
My best advice to someone who is fighting poor soils is to to find a horse training facility nearby and make a deal with the owner to carry off some of their stall waste.