Many many years ago, my father and I buried around 50 carp in the garden I shot with the bow. He used the furrowing attachment for his roto tiller to dig deep trenches. Laid the fish in and covered. That year the pepper plants were over shoulder high. Had to cut them out with an axe that fall. Hardly any peppers though. Found out later pepper plants do better in poorer soil
The rest of the garden grew great for several years after that. Now I just bury my trimmings in the compost heap and use that in the garden.