* Mineral particles: These are the breakdown products of the parent rock, including clay, silt, and sand.
* Organic matter: While less abundant than in the topsoil (A horizon), the B horizon contains some decomposed organic matter that has leached down from above.
* Iron oxides: These are reddish-brown compounds that give the B horizon its characteristic color in many soils.
* Calcium carbonate: In some soils, calcium carbonate can accumulate in the B horizon, forming a hardpan layer.
* Other minerals: The specific mineral composition of the B horizon depends on the parent rock and the weathering processes that have occurred.
Key characteristics of the B horizon:
* Accumulation of materials: The B horizon typically has a higher concentration of clay, iron oxides, and other minerals than the A horizon due to leaching and deposition from above.
* Less organic matter: It contains less organic matter than the A horizon because it's further from the surface where plant roots and microorganisms are active.
* Lower biological activity: The B horizon has less biological activity than the A horizon due to lower organic matter content and less available water.
It's important to note that the composition and characteristics of the B horizon can vary greatly depending on the soil type, climate, and other factors.
