What does the presence of a B horizon typically indicate?

The presence of a B horizon typically indicates the accumulation of materials leached from the above layers, such as clay, iron, and other minerals. This horizon often exhibits a denser and often stickier texture compared to the A horizon due to the higher concentration of clay particles. As a result, this layer can influence drainage and moisture retention in the soil. Additionally, plant roots may be found extending into the B horizon, as they seek nutrients and moisture that are present in this layer.

The B horizon plays a crucial role in soil fertility and structure, as it serves as a transition layer where the effects of weathering and leaching accumulate. This horizon is characterized by its reduced biological activity compared to the A horizon, which often contains more organic matter, but its physical properties and mineral content are critical for supporting plant growth.