My ecosystem of organic gardening depends heavily on coffee grinds, egg shells, junk mail, and green clippings. Coffee grinds kill off the slugs with caffeine toxicity. The earth worms love grinds. The junk mail goes in a five gallon bucket, ground up into a slurry along with egg shells and kitchen scraps.
If you add some finally ground charcoal (real charcoal, not with fuel additives) all of those nutrients will last for 1000 years in your soil. Look up “biochar.“