Which soil horizons are typically present in a soil profile?

The presence of specific soil horizons in a soil profile helps to categorize and understand the complexity of soil formation and characteristics. The options presented include various combinations of horizons, but the one that is most widely recognized is the combination of O, A, E, B, C, and R horizons.

The O horizon, also known as the organic layer, is composed mainly of organic matter, such as decomposed leaves and other plant materials. It plays a crucial role in the ecosystem by contributing nutrients and improving soil structure.

The A horizon, or topsoil, is rich in organic material and nutrients, making it the most fertile layer, essential for plant growth. Below this is the E horizon, which is characterized by the leaching or eluation of minerals and nutrients, resulting in a lighter color and less fertility.

Following the A and E horizons is the B horizon. This zone, often referred to as the subsoil, accumulates minerals and organic material leached from the upper layers, indicating a process known as illuviation.

The C horizon consists of weathered rock and unconsolidated material from which the soil forms. Finally, the R horizon is bedrock, providing a foundation for the soil profile and influencing its characteristics.

This sequence of horizons