In soils with distinct soil horizons the bottom zone is the subsoil. This zone lies below the topsoil (the upper layer) and is characterized by the accumulation of minerals, clay particles, and other weathered material. The subsoil is typically denser and more compact than the topsoil, and has a high concentration of nutrients. It plays a crucial role in the transport of water and nutrients to the plants as well as providing support to the topsoil.