Lighter colored soils are a sign that over the years erosion has taken its toll. Wind erosion is highly visible. Although it is a problem, water erosion is generally much more severe. Rill erosion occurs during heavy rains, when small rills form over an entire hillside, making farming difficult. Gully erosion makes gullies, some of them huge, impossible to cross with farm machinery.
Ephemeral erosion occurs in natural depressions.
It differs from gully erosion in that the area can be crossed by farm equipment. The most effective way to control erosion is to maintain a permanent surface cover on the soil surface, such as pasture or meadow. Therefore, areas that are highly susceptible to water or wind erosion need to be considered for soil conservation programs. Soil losses in Iowa due to water erosion and surface runoff can contribute a great deal to surface water quality concerns. Many studies indicate that soil erosion results in large decreases in soil productivity.