How To Get The Top Foot of New Soil Mixed Up?

I am having the top foot of soil removed and replaced as part of a remediation project next to an EPA Superfund site. The standard they are providing us neighbors is 9 inches of sand covered by 3 inches of topsoil. (This is an example from a neighbor's yard.)



Since my 1/2 acre yard will be replanted full of fruit & nut trees and other edibles, I am putting together a better soil mix - 15% clay, 40% sand, 40% topsoil, and 5% compost. The question is, once these layers are deposited, how to mix them up? As you can see, there is nothing tough to cut through - no rocks, no hardpan, no sod, nothing - it's like starting from a blank slate. It just needs to be mixed up, but most tillers it seems can only go 6-8 inches deep. Alternatively, if I am stuck leaving the bottom 4-6 inches unmixed, what should I do? Put the sand on the bottom, and use the clay, topsoil and compost to be mixed on top? I live in North Central Florida, and our natural soil is extremely sandy with very little clay. Thanks for any help!

Welcome to Permies, Kayla!

Get some pets. Maybe some of these



or some of these



or if you don't like the look of those, maybe try these



Actually, if you have a lot of the first, the second will come looking for them. And the third. Since what they are bringing in and laying down is probably going to be pretty close to sterile, it would be good to get some soil life in there ASAP. When the soil is alive and has a full complement of soil fauna, it will get mixed up on its own through the actions of all the fauna moving around, digging and tunneling.

It looks like they are spreading the soil out nicely and not compacting it, which makes life easier for burrowing animals. The only other thing that burrowing animals would like is maybe a couple of inches of leaf litter to hide under. You could get that from a tree trimming service, just tell them they can dump a load of trimmings on your property. If you lay some pieces of well-rotted logs out, that may provide additional cover for ground dwellers. I have all sorts of new holes popping up in the garden where some resident has decided to put in a front door. I generally leave these alone, since I want to encourage the toad population.