I learned a lot from this article about dryland farming. Since it’s from the Food and Agriculture Organization (FAO) I’m inclined to trust what this article says. But I don’t see a date on the article. It cites 20th century sources of info, so I don’t know how up-to-date it really is. Here’s an article from last year, about Australians offering dryland training to African farmers.
You can follow my ‘dryland’ and ‘desert’ tags for more about growing food in dry places.