In which soil horizon does leached material from the A horizon accumulate?

The B horizon, often referred to as the subsoil, is the layer where leached materials, such as nutrients and minerals, accumulate. This horizon is below the A horizon (topsoil), which is rich in organic matter and minerals. As water percolates through the A horizon, it can dissolve and transport certain elements downwards. The process of leaching removes these materials from the upper layer and deposits them into the B horizon.

The B horizon acts as a zone of accumulation, where minerals like iron, aluminum oxides, and clay particles may concentrate. This accumulation is significant for soil fertility as it can influence the availability of nutrients to plants. The characteristics of the B horizon can vary widely depending on the soil's parent material, climate, and vegetation cover, but its primary function as a reservoir for leached materials is a key aspect of soil development and function.

Other options represent different soil horizons with distinct roles. The C horizon consists of weathered rock material and unweathered parent material, while the O horizon primarily contains organic matter such as decomposed leaves. Since these horizons do not play a primary role in accumulating leached materials from the A horizon, focusing on the B horizon provides a more accurate understanding of soil processes related to le