I think for a lot of homesteaders and builders, even in use around WOFATI's; Earthcrete has its place, and I feel so strongly about that, that when I did my classes on sheep farming, I mentioned Earthcrete.
Earthcrete is using the existing soil, then mixing it with Portland cement, and then mixing in
water and letting it harden. It can be mixed in a cement mixer too, but the greatest advantage of Earthcrete is in vast slabs. That is because it is so easy and cheap to make. A cement mixer is not even required!
All you do is take a rototiller and till up the soil to a consistent depth, say 4 or 6 inches. Then calculate how many bags of Portland cement you need to make an earthcrete slab that size and depth. I use 5 bags of Portland cement per cubic
yard (27 cubic feet) of earthcrete. Spread the cement powder out as even as you can, and then rototill again until the earth/cement is consistently mixed. Now using a hose or buckets of water, add in the appropriate amount of water, and mix again with the rotortiller. After that, the earthcrete is troweled and finished just like you do any other
concrete project. And by the way, if you do not have a rototiller, they can be rented for a project like this.