The intention was to spread the manure over existing dirt/clay and then
till
it all together. I'm no expert but the land had wild grass and weeds
growing
on it before I started the project. It all went south once the machinery
packed the top layer too hard (approx 50% of the area) so the tiller could
not mix the manure with the dirt anymore. Even when the tiller managed to
break some test areas the chunks are very hard. Will I have any luck
breaking up the hard shell in the spring once the ground is more moist of
will watering help?

So there's good soil beneath the clay? That bites -- what commercial
contractor digs out a basement but doesn't haul off the excavated materials?
Bummer Hmmmmm....

How deep is the clay layer that was placed over top of the soil? Any idea
how deep the soil below the clay might be?

I'm tellin ya -- the best thing you can do is buy a BUNCH of worms and just
spread them over the area. Eisenia Fetida (http://www.happydranch.com)
needs 50ish degree weather to do its thing but if you get them down now they
should do a good bit of work before it gets too cold and they'll likely
overwinter fine (not sure where you're at). Earthworms/nightcrawlers will
dig down well and there's one worm in particular that goes down to around 12
feet. As they dig through the soil and the clay, they'll take nutrients
along with them and help convert the clay to good soil the old fashioned
way.

You also need to mulch up leaves and grass to spread over the area for
composting. Now is a perfect time as everyone is throwing their leaves
away -- a pickup truck on trash day is a good way to go. I know it sounds
crazy but you'll get all sorts of good organic material this way. You can
hit your neighbors up and ask them to save the leaves for you as well --
makes it easier and ensure no mix of trash with the leaves. You can buy a
leaf mulcher for around $100, mulch the leaves up, and spread them about.
The worms will love that as well.

If you do this and keep it up, maybe add some more compost and/or top soil
next year, working it into the existing, then you will not have to worry
about tilling the clay.

Do you figure I will have any luck if I seed in the spring on the manure?

It should be fairly well broken down by then but I doubt it will be quite
enough. Just how deep IS the doo-doo? (Sorry, couldn't resist. :-P )
Grass will need about 6 inches or so to do well.

BTW, the following came over the CrazyGardeners1 Yahoo group recently --
since it may have value for your situation, I thought I'd cross-post it for
your edification.

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Yuuupppp! Green manure is a great way of building topsoil when all
you have is clay, sand, or other nasty soil. The most basic of all
green manure rotations is BOP-BOP-RYE, which is Buckwheat Oats and
Peas, followed by Buckwheat Oats and Peas, followed by winter rye.
The buckwheat adds TONS of organice matter to the soil, the peas add
nitrogen, and the oats gives structure. The winter rye holds the
soil in place and also gives excellent structure to the soil due to
its rather tough stems. But there are better choices once you have
started investigating, and are willing to work out what your
particular soil needs.

Red mammoth clover, for instance, not only gives tons of organic
matter, but nitrogen as well, and sudan grass can not only give
organic matter, but feeds the beneficial bacteria and fungi as it
repells and kills bad nematodes. Daikon radish is GREAT for digging
in deep and when tilled in will rot and creat an ideal spongy mass
underground for sandy or clay soils. Organic matter right where you
need it...Down deep. Alfalfa is also great at digging deep into the
soil where you need it, fixing nitrogen farther down than clover, and
loosening clay and binding sand. There are even cover crops for
shade, subterranean clover, daikon radish, peas, vetch, Lotus
uliginous (Mako lotus) is excellent for shade, but hard to find.

I like to simply mow the crops just as they begin to flower, and then
seed the new crop right into the fresh chopped matter, to leave the
roots and the beneficial fungi and bacteria web alone so it can
spread effectively. Another thing you can do is to use the green
manure crops as forage for your rabbits, goats, horses,
cows...whatever, and let them add to the organic matter with their
droppings. I actually plant a couple of hills on my property with
browse cover crops for the deer, so they will give me the droppings
and STAY THE HECK AWAY FROM MY HOSTAS! So far it works. Even the
woodchuck would rather eat the nice fresh oats and barley than invade
the garden.
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