The B horizon, also known as the subsoil, is the layer of soil that lies between the topsoil (A horizon) and the parent material (C horizon). It is typically denser and more compact than the topsoil, and has a higher concentration of clay and other minerals. The B horizon is often where water and nutrients are stored, and it is also where roots grow.

Here are some of the characteristics of the B horizon:

* Color: The B horizon is typically darker than the topsoil, due to the presence of organic matter and iron oxides.

* Texture: The B horizon is usually finer-textured than the topsoil, due to the higher concentration of clay and other minerals.

* Structure: The B horizon is often blocky or prismatic in structure, due to the presence of clay minerals.

* pH: The B horizon is typically more acidic than the topsoil, due to the leaching of nutrients and organic matter.

* Nutrient content: The B horizon is typically less fertile than the topsoil, due to the leaching of nutrients.

* Water content: The B horizon is often where water is stored, due to its higher concentration of clay and other minerals.

* Root growth: Roots often grow into the B horizon in search of water and nutrients.

The B horizon is an important part of the soil profile, and it plays a vital role in the storage of water and nutrients, and the growth of roots.