ECOLOGY OF SOIL-EROSION IN ECOSYSTEMS

Each year, about 75 billion tons of soil are eroded from the world's t errestrial ecosystems. Most agricultural land in the world is losing s oil at rates ranging from 13 tons/ha/year to 40 tons/ha/year. Because soil is formed very slowly, this means that soil is being lost 13-40 t imes faster than the rate of renewal and sustainability. Rain and wind energy are the two prime causes of erosion from tilled or bare land. Erosion occurs when the soil lacks protective vegetative cover. Soil e rosion reduces the productivity of the land by loss of water, soil org anic matter, nutrients, biota, and depth of soil. The greatest threat to providing food for a rapidly growing human population is soil erosi on. Abandoned, eroded agricultural land is replaced by clearing forest ed ecosystems.