Answer:
Modern irrigation systems, redirecting of streams or parts of them, and using drought resilient plants, will help gradually convert the desert and make it suitable for farming.
Explanation:
A lot of countries in the world have problems because a smaller or larger part of their territories is occupied by deserts, and on top of it, it seems like the deserts are expanding. The deserts as they are cannot really be used for anything, including farming, but this can be changed in managed properly.
In order to convert desert into land suitable for farming, a good and reliable irrigation system needs to be set up, at least for the first few decades. Ares that are relatively close and maybe have a surpluss of water, or it is a terrain where it cannot be used for farming or anything practical, the streams can be redirected toward the desert. This will bring in highly fertile sediments, a constant supply of water, and increasing humidity in the area. The plants that initially need to be used should be ones that are highly resilient to high temperatures and drought, but also leave a solid amount of biomass so that the soil can get a fertile top layer. Plants that can be very suitable are rosemary and succulents, and they will also be economically beneficial in the meantime while the transformation lasts as they can be easily sold on the market.