Like Dale, I have applied generous amounts of coffee grounds right to the soil and tilled it in with good results. I also add a lot to my compost bins. To date I haven't seen any negative results.
In my own situation, the big trucks decline dumping chips right onto my farm because the fear lava tubes might be under the surface of my
land, something I can't guarantee one way or the other. Historically in my region, heavy equipment has been known to fall through those tubes. Therefore I have chips dumped along the roadway and simply spend the afternoon running back and forth hauling small loads back to where I want them. Yes it takes time and effort, but the reward is a truckload of fresh mulch for the growing areas.
Living rural, I can forage biomass. I simply get permission from the landowner. I can bring home lots of fallen fruits, or if I wish, machete lots of tall grasses to cart home.
I also provide clean, lidded buckets to various local food establishments for collecting any sort of food waste, I pick up 5 days a week. Where I live, I don't need a permit to do this.
I have many people who collect their old newspapers for me. Usually once a month we make a point to meet somewhere, like the local post office or supermarket, to exchange the paper. Many folks also save me their
cardboard, paper egg cartons, and such. And a few save me their kitchen waste, which they freeze in plastic bags between deliveries.