I've got a brand new, empty raised bed in the backyard. It's on the south side of my house, in full sun, and I built it out of 50/50 topsoil/compost. It's roughly 4 feet by 12 feet, and after a full winter's compaction it's roughly a foot and a half high.
The native woodland soil was scraped away when my house was built in early 2005, so this new raised bed was built over grass which is basically growing on gooey grey/blue clay.
Out in the garage I've got ~60 lbs of glacial rock dust, ~50 lbs of greensand, ~40 lbs each of rock phosphate & azomite, ~30 lbs of agricultural gypsum, ~20 lbs each of kelp meal, alfalfa pellets & bone meal, ~15 lbs of Cowboy Charcoal (suitable for making biochar), & 10 lbs of Sea Agri sea salt. I've got a pound of mycorrhiza (beneficial fungus) mix, packaged in 2010. I also have a pound or two each of the following inoculated cover crop seeds (from 2010): yellow berseem clover, white clover, crimson clover, hairy vetch, biomaster peas, & buckwheat.
I've got many, many packets of veggie & herb seeds, a compost pile that's about 4 x 3 x 10 feet, and lots of unplanted bulbs from November.
If you were me, what experiments or trials would you conduct? I'm willing to spend another $50 for plants if a really cool idea requires it.