What are the solutions for desertification?

The prime cause of desertification is loss of ground cover. Thus, any strategy which seeks to enrich, sustain, and promote growth of ground cover plantlife will halt desertification. In most areas, this means promoting some sort of grass; remember, there are a huge variety of grasses (including many types of food-producing plants). Grasses enrich the soil, as well as providing a protective mat holding the soil in place.