Soil, together with water and air, is one of the three key natural reserves. Without soil, there would not be any form of natural vegetation or life. Soil comprises of layers of varying depth and form. The ratio of each of these components is vital in establishing the type of soil present in an area. Other factors such as climatic conditions, nearby topography, human activities and so on also determine the soil type. The basic types of soil layers are as follows:

Organic matter

This layer is the refuse layer of moderately unfortified plant remains.

Surface soil

The mineral soil layer has the most organic matter collection and soil life. It is devoid of clay, aluminum, iron, organic compounds and other dissolvable components.

Subsoil

The Subsoil layer accrues clay, magnesium, iron, aluminum and organic compounds via a processed known as illuviation.

Parent rock

The parent rock layer consists of large complete rocks, and it accrues more soluble compounds.

Attributes of SoilWhat is Soil Made Of?

The first striking attribute of soil is its color. Depending on the soil mineral composition, soil color differs from area to area. Iron minerals also play a major role in the coloring of soil. Other factors include chemical and biological conditions.

Soil structure is the assembly of soil elements into different segments. These segments are of different sizes and shapes. Soil structure greatly influences water passage, aeration, erosion prevention, vegetation growth and so on. It also presents clear indicators about preceding soil development, impact of human use, biological activities and so on.

Soil texture is the arrangement of sand, clay, and silt. These constituents influence the soil’s ability to retain water and vital nutrients. Clay has better ability than sand and silt to preserve water and nutrients, as it is capable of withstanding wind and water erosion. This is due to the fact that clay particles are more firmly connected with each other.

Categorization of Soil

Earlier soil was classified into different types based on its parent materials and soil formation aspects; modern classification of soil is based on soil evolution. Soil, based on the current United States classification system, is categorized into different orders. They are as follows:

  • Entisol
  • Vertisol
  • Aridisol
  • Mollisol
  • Spodosol
  • Alfisol
  • Ultisol
  • Oxisol
  • Histosol