Soil erosion is the main reason why desertification is irreversible. Vegetation can regenerate from a degraded state as long as the seed stock remains viable and there is soil for seeds to germinate and grow in.

Water and wind are the two main mechanisms by which soil is eroded and transported. Of the two, water has proven experimentally to be the most important in causing soil erosion with long-lasting results. Controlling water erosion, within overall integrated desertification control plans, is thus a top priority if land productivity is to be maintained.