Sand, silt, clay and soil loss

Healthy topsoil is precious. Soil is lost when it is eroded by water and wind, or when it is used up. Farming without care, cutting down forests, long droughts and overgrazing can all leave the soil bare. Bare soil is easily carried away, and land that was fertile can slowly turn to desert. This is called desertification. Three things affect erosion: the slope of the land, the amount of water that flows over it, and the plants that cover it. A steep slope and a lot of water carry more soil away. Plant roots hold soil together, leaves slow the rain, and trenches or steps cut across a slope slow the water down. Planting trees and grasses, and adding compost or crop remains, help restore soil. If people look after the land, we can slow soil loss.