Facts About Soil Erosion

Water Runoff & Soil Erosion

• Soil erosion involves the gradual deterioration of soil amounts and quality. Soil erosion can occur when rainwater runs down sloping land that doesn't have enough vegetation to hold it back, or when the soil doesn't have the composition that allows it to absorb water. Flooding can cause major disruptions in soil composition and runoff.

Other Causes of Soil Erosion

• Strong, constant wind can sweep over bare soil, lifting it into the air to be deposited elsewhere. Even wildfires can cause soil erosion, when the intense flames heat the soil into a condition that repels water. This condition is called hydrophobia. It occurs when the burnt vegetative matter forms a gas that cools and become a waxy coating on the soil. This coating increases water runoff and makes it difficult for new seeds to germinate. Fire also destroys the vegetation and plant litter that helps protect soil.

Why Soil Erosion is Important

• Soil erosion removes the enriched topsoil, which consists of decomposed vegetative matter that provides nutrients for crops. When this topsoil is depleted by water runoff, plants cannot grow, flower and produce fruit. This also affects soil water availability, root growth and plow layer fertility, according to an Iowa State University study. In addition, the topsoil then flows into waterways as sediment that disrupts the free flow of water for communities, wildlife, and other plant-supporting environments.

Ways to Prevent Soil Erosion

• Planting vegetation thickly helps hold soil in place, the root system impeding the flow of water over land. Plants that crawl and spread are better for soil protection than those that grow upright. Matting material can be used to cover areas with serious erosion problems. Retaining walls and edging can help prevent soil displacement from water runoff. Mulch can help rainwater soak into the soil slowly instead of flowing off quickly and carrying soil with it. Constructing terraces on slopes to restrict and slow water runoff can also help prevent erosion.