Alfisol

Alfisols are a special kind of soil that are very important for growing food and plants. They are found in areas that are not too dry and not too wet, often under forests with hardwood trees like oak and maple. These soils have a lot of clay in the lower layers and are good at holding nutrients, making them great for farming and growing trees.

The name “Alf” comes from the elements aluminium and iron, which are found in these soils. Alfisols cover about one-tenth of the Earth’s land that isn’t covered in ice. You can find them in many places, such as the Ohio River basin in the United States, parts of Europe, India, Sudan, and South America.

Unlike some other soils, Alfisols have not lost too many of their useful minerals through water washing away, which means they still have plenty of calcium, magnesium, and potassium. This makes them more fertile than other soils found in rainy areas. Because of their richness, Alfisols have been supporting forests and crops for a very long time, even since ancient times.

Suborders

Alfisols have different suborders based on where they are found and their climate.

• Aqualfs are soils that stay wet for long periods, which can make it hard for plants to grow because there isn’t enough oxygen in the water. These areas were mostly forests in the past. Redoximorphic features can be seen here.
• Cryalfs are found in cold, high places where temperatures stay between just above and below freezing.
• Udalfs grow in places with a lot of rain or just a bit less, and these areas were also forests long ago.
• Ustalfs are in drier places that have wet summers and dry winters.
• Xeralfs are found where summers are very dry and winters are wet.

Fossil record of Alfisols

Alfisols have been found in fossils dating back to the Late Devonian period. These ancient soils were formed under early forests. In Antarctica, scientists found signs of trees in Alfisol-like soils from this time.

In New York, fossils of ancient trees show how these early plants lived. Some trees needed more water than others, and their roots helped shape the soil below.

In Argentina, fossils of forests were found in Alfisols. These forests were made of tall trees with wide, spreading roots. Scientists also found traces of bees and termites in these ancient soils.