Final answer:
The A horizon is considered the topsoil and the B horizon is the subsoil in a typical soil profile. Soil structure is influenced by relief, drainage, and management practices including tilling and no-till farming. Soil color varies with drainage conditions and organic matter content.
Step-by-step explanation:
The question pertains to soil management and development, which is related to the field of Geography and, more specifically, soil science. When examining soil profiles, the O horizon is typically the uppermost layer consisting of organic matter, while the A horizon is considered the topsoil and is crucial for plant growth due to its richness in nutrients and organic material. Below that, the B horizon is recognized as the subsoil, which contains minerals leached from the topsoil but is less fertile and has less organic matter. The C horizon lies beneath the B horizon, consisting mainly of weathered parent material.
Soil structure is significantly influenced by various management practices and natural processes. Soil drainage, organic matter accumulation, and vegetation are all influenced by the local relief and drainage conditions, which can lead to soil erosion or the development of more fertile lands. In historical contexts, land management practices like 'flipping' refer to the economic strategy of improving and selling land, not to specific soil orders. Practices such as no-till farming, often contrasted with conventional tilling, aim to maintain soil structure, preserve soil moisture, and prevent soil erosion. Various practices can affect the color and composition of soils, with well-drained soils exhibiting more brownish or reddish hues, while poorly drained soils can appear greyish or dark due to iron reduction and organic matter preservation.