What are the soil horizons in the correct order from top to bottom?

The correct order of soil horizons from top to bottom is O, A, B, C, R.

The O horizon, often referred to as the organic layer, is typically the topmost layer and consists primarily of organic matter such as decomposed leaves and other plant material. This layer is crucial for soil fertility as it contributes nutrients and supports a rich ecosystem of microorganisms.

Beneath the O layer, the A horizon, also known as topsoil, is where most of the soil's biological activity occurs. It is a mixture of organic material with mineral particles, making it fertile and vital for plant growth.

Following the A horizon is the B horizon, often referred to as subsoil, which accumulates minerals leached from the upper layers. This layer plays an important role in storing nutrients and water that can be accessed by roots.

The C horizon is a layer of weathered rock and parent material from which the soil forms. It has not undergone significant soil formation processes and is generally less developed compared to the layers above.

Finally, the R horizon is bedrock. It is solid rock that serves as the source material for soil formation but does not contribute directly to plant growth.

Understanding the correct order of these horizons helps in soil management practices,