I have tried to bury kitchen scraps, dead plants and any woody material (old wood, carton paper, dried and chipped Arundo). All of this does help earthworms to

I have tried to bury kitchen scraps, dead plants and any woody material (old wood, carton paper, dried and chipped Arundo). All of this does help earthworms to multiply. The change in soil structure was noticeable after deep digging, removing stones and planting potatoes and cover crops (phacelia and rye). Cover the surface with mulch / dead plants material otherwise the sun will bake it to brick-like thing. This was on a small scale < 100m^2 and frankly without at least some good soil from the outside it is a long, uphill battle to grow plants in it.