It's hard to tell which thing made the biggest difference on this hectare. There was an initial round of grading/earthworks on much of the property, but otherwise it has been no-till, chop and drop (or throw into a nearby pile) and hand managed - no burning save turning a limb pile into a half yard of charcoal. These unnammended soils do look better than the former lawn, but 5+ years later and it's still not fertile enough to grow anything other than some hardy greens or trees.
The biggest difference is probably the mycelia feeder or "Super Duper Hugel Pooper" as I like to call it.
Like, 6" of strawish stuff, in a foot deep trench on a local elevation maxima, between a few foot+ diamater logs set on the ground (the walk n squat rails) which then gets filled with compressed humanure wood chip matrix (fresh septic trench compresses like a pile of woodchips if stepped on.) In the first growing season after capping toilet sites with a few inches of poor topsoil, they were dominated by clovers, suggesting the C:N ratio is C heavy in a my "compressed poo- chip matrix." Interesting how turning hot manure into a thin layer with nearly maximized surface area contact with wood, totally alters the decomposition process. After the first year of clover and a few hardier plants, Super Duper hugel Pooper sites support high yield squash, tomatoes, and broccoli. I'm pretty sure they would support high yield anything, but root vegetables are not recommended XD
There's also like, 500 lbs of primo fertilizers, 12 yards of finished horse manure, 10 poultry worth of manure for 6 or so years, and something like 50 yards of wood from the site was returned to the soil. Apart from the wood, none of this stuff was added to the toilets.
If a "long run" is 5 years, the super duper hugel pooper is definitely the biggest soil difference. It makes significant calories now. However, if "the long run" is more like 10 or 20 years, most of the other inputs that have been slowly added added over 7 years could be the bigger difference, but I won't be here to see the 55 seed started fruit and nut trees grow up. There 15 or so that are 15' tall, otherwise the trees are still popping off 3 or 4 at a time each year. They had a mostly rough start in some fresh hugels, or a rough life thus far; 9 of the trees are still knee high 5+ years later.
These ones are almost certainly stuck in a hardpan bowl. Transplant or no, there was never going to be a taproot there XD
That is, until something happens. Swales which changed water flows and then caused ~50 to 100 ft^2 sections of hillside to moves a few inches, and then a tree pops off, or some perennial broccoli rabe plants are growing off irrigation and surviving a summer without rain...big difference!