Desertification is the process of fertile land transforming into desert due to factors like climate change, overgrazing, deforestation, and overcultivation. It affects one third of the world's land and millions of people. It degrades soil quality, reduces vegetation and biodiversity, and causes problems like drought, famine and poor water quality. Solutions include sustainable agriculture, controlled grazing, crop rotation, land management practices, and tree planting to reduce erosion and manage dry land resources.