Lots of natural sources for Phosphorus: "Besides human urine, there are many naturally occurring sources of phosphorus that can be used in the garden, including bat guano (or feces), bone meal, crab and shrimp waste, burned cucumber skins, hair and mushroom compost. ". I put bone meal in the bottom of every hole I dig to plant a plant, and I think that keeps my soil phosphorus levels up.
The agricultural revolution was accomplished without petroleum based fertilizers, so I'd think yes.
I can see England becoming the Nettle Compost Tea producer to the world. I've never seen such a country for nettles.