you could try different plants. i have a really sandy and sour soil here, potatoes, fava beans, and miners lettuce are doing well, everything else not so much. my pumpkin/squash is barely growing, corn is only doing okish. my onions and tomatoes aren't doing so well either. fava beans have the perk that they fixiate nitrogen.
@giru @mangeurdenuage where are you from? in germany there's bingenheimer saatgut (who seem to share a spirit with kokopelli), they say that they ship to other countries, too: https://www.bingenheimersaatgut.de/en/info/en/about-us/about-us.html
@giru @mangeurdenuage
yeah, that should be no problem :)