What is soil erosion?

Erosion is a process that removes soil layers and carries them away from farmer's fields to bodies of water or other land. Erosion results in the loss of valuable soil and its nutrients that are necessary for crops to grow. There are three primary kinds of erosion: wind, water, and tillage. In areas where the land is especially flat or dry, wind erosion is a problem. As wind blows it spreads soil particles across the land.

Soil is naturally removed by the action of water or wind: such 'background' (or 'geological') soil erosion has been occurring for some 450 million years, since the first land plants formed the first soil. Even before this, natural processes moved loose rock, or regolith, off the Earth's surface, just as has happened on the planet Mars.

Water erosion may occur gradually during rainfall or when winter snow melts in fields. It can also happen suddenly during floods.