What Are the Top Three Soils & Why?

Inceptisols

• No class of soil support more people all over the world than the inceptisols. Approximately one in five people are supported by inceptisols. No other class of soil supports so much of the human population. This is in large part due to the fact that these soils are so widely distributed. They are the second most common type of soil in the world, covering 15 percent of all ice-free land. Although inceptisol soils are found in all kinds of environments, they are commonly formed on steep slopes, floodplains, river deltas and river banks.

Inceptisol Appearance and Location

• Inceptisols have layers of different materials under the surface. Though these layers have different colors they are poorly defined, with one layer blending slowly into the next. The fuzziness of the layers is due to the youth of these soils. These layers have different colors because they are formed of different materials: sodium, silicon clay, white clay and various metal oxides. Inceptisols are mostly found in the eastern and northwestern parts of the United States. They are mostly well drained, but many of those in the east are waterlogged.

Alfisols

• Alfisols are highly fertile soils that are widely used for agriculture. The Chinese and European peoples have used them for farming for thousands of years. About 17 percent of the world's population is supported by alfisol soils. They are generally well drained and maintain a good balance of moisture.

Alfisol Appearance and Location

• Alfisol soils have a layer of clay below the surface. They also contain layers with sodium in them. In the United States they are found in heavy concentrations in a stretch along the Mississippi river and scattered in various other locations throughout the country.

Mollisols

• Mollisols are some of the most fertile soils in the world. They are formed under grasslands. Mollisols contain large amounts of organic material deposited in the soil by the roots of previous generations of grass, which is responsible for its high fertility. They are often used to raise grains, corn, soybeans and sorghum.

Mollisol Appearance and Activity

• Mollisols have layers that range from dark brown to black. They are granular and soft to the touch. They are the most common soils in the United States, where they are found mostly in central and western regions.