Which of the following soil types typically lack horizons?

Entisols are characterized by their minimal development of horizons, which are layers in the soil that differ in physical characteristics, composition, or biological activity. This lack of distinct horizons occurs because Entisols are often found in environments that are newly formed or have undergone disturbances, such as riverbanks, floodplains, and areas with constant erosion. They usually contain little to no profile development due to factors like parent material composition, climate, or geological processes that prevent the formation of more developed soil layers.

In contrast, other soil types like Ultisols, Inceptisols, and Histosols possess varying degrees of horizon development. Ultisols typically exhibit distinct horizons due to their significant weathering and leaching processes, while Inceptisols often show weakly developed horizons. Histosols, which are composed mainly of organic matter, also have recognizable layers but are defined differently based on their organic content rather than the absence of horizons. Thus, Entisols stand out due to their simplicity and lack of horizon development.