The main problem is the lack of industrial installations for the production of drinking water from the air. There are many homemade devices. They can be found on the Internet. To date, the best option is to built wells to get water from the air.They were built in the Middle Ages on the Great Silk Road. With environmentally friendly processing of food waste and human life waste into hygienic clean compost, organic fertilizer and other products, there are no problems today.
We are collaborating with Maged Saad from KAUST, Saudi Arabia, in a project on optimizing stress tolerance of plants in desert conditions through the study and cultivation of beneficial rhizosphere microbes. Have a look here: https://cda.kaust.edu.sa/Pages/ResearchProjects.aspx and here: https://cda.kaust.edu.sa/Pages/Maged%20M.%20Saad.aspx
I recommend contacting Maged directly, he's usually very open to outreach.
Unfortunately there are no easy answers, and what works in one location is not necessarily the answer for the next. Over and above answers given by others, things to try are:
Prevent/limit overgrazing by livestock
Select suitable livestock, eg. donkeys create havoc to grasslands, while camels dont
Establish suitable flora if possible
Diversification of livestock and crops
In Namibia some useful work has been done by the Desert research Foundation of Namibia and the Ministry of Agriculture.
Dr Axel Rothkegel has done some useful work on the managing of grazing land, including limiting of bush encroachment and establishing the correct flora.
The City of Windhoek recycles sewerage water to drinking water standards, as well as using grey water for parks, sport fields and other green areas
The Elephant in the Room is disposal/loss of once-use Water as pollution by Marine Outfall, when onshore re-use just makes good sense, more attached ...
We have been presenting to the worldwide community a process for the generation of potable water which relies on room temperature evaporation through our website www.naturalseawaterdesalination.com. Room temperature evaporation is the only available physical phenomenon which allows the separation of pure water out of any saline water WITHOUT THE SUPPLY OF ANY EXTERNAL ENERGY. The energy needed for this separation is obtained by cooling the bulk of water.
Room temperature evaporation is the process by which The Creator is availing for us pure rain water, The Creator is still the biggest supplier of pure water. All the rivers on our planet are getting their waters from Room Temperature Evaporation, and here we are today with the capacity to avail enough potable water for the size of a river.
Our equipment is very simple and consists of a tower water cooler and a heat exchanger, our energy consumption is less than 3 kwh/cubic meter of generated potable water, and our equipment is cheaper than the Chinese single stage units of Reverse Osmosis.
There are many techniques that have been published dealing with desert reclamation technologies and also best practices for soil amendments, binding up chlorides, innovative drip irrigation, morning mist harvesting, using white ground cover materials (not black) to retard evaporation, use of permeable shade cover, the list of good practices is extensive however, there are very few that deal with "cultural prohibitions" that prevent enlightened environmentalists from using some of these practices as some of them are widely accepted, e.g. use of stabilized sewage sludge that came from pig farms, and human feces. If there is a willingness reclamation can happen. Sludge from New York City gets pelletized and is shipped by rail to Florida where it is an amendment to citrus crops grow in sandy soil. You cannot tell Islamic countries that something worked in Israel as that almost certainly means it will not be considered no matter how viable an alternative to expanding agricultural lands into what is desert. With China increasingly willing to invest in desert reclamation their economic prowess might be enough to overcome cultural prohibitions.