This document discusses soil erosion, its causes, effects, and methods for prevention. It covers: - Natural and human-caused soil erosion, with the latter including overcropping, overgrazing, and deforestation. - Problems from erosion like loss of topsoil and declining plant productivity. - A case study on erosion and desertification in Africa's Sahel region exacerbated by climate change. - Conservation methods like windbreaks, contour plowing, stubble planting, terraces, and stone walls.