Soil Water

Soil water is mainly found within the pore spaces of the soil. It competes with air for pore spaces and therefore occupies the pore spaces not occupied by soil air. It is also found in the spaces between the mineral grains of the soil.

Organic Matter

Soil organic matter is an important component of soils; although it constitutes only about 5% of total soil composition of mineral soils (it could constitute as much as 95% in organic soils like peat, muck etc). Along with mineral matter, it constitutes the soil solids.

Mineral Matter

Mineral matter is the predominant component of mineral soils. It constitutes about 45% of total soil composition. It is made up of a number of particles which vary in size, shape and chemical composition. These particles range from the microscopic colloidal clays to the coarse fraction of sand and gravel. In nature, mineral matter exists as a dispersed phase, implying that it can be separated into the individual particles that comprise it. Along with soil organic matter, it makes up the solid materials phase of the soil.

Soil Air

Soil air is an important component of soils. It occupies those pore spaces not occupied by soil water. Soil air competes with soil water for the pore spaces in the soil, hence it moves in as water moves out.

Chemical Weathering

Chemical weathering is a type of weathering that primarily results in changes to the chemical composition of rocks and minerals. These chemical changes could also result in changes to the physical attributes of the weathered products.

Physical Weathering

Physical weathering is a type of weathering whose major impact is the reduction of larger rocks and minerals into smaller sized particles. This reduction exposes a larger surface area of the rocks/minerals to more weathering (both physical and chemical).

Weathering

Weathering is the group of processes whereby rocks and mineral, on exposure to weather, change in character, disintegrate, decompose, and synthesize new compounds. It generally involves two stages or phases.

Composition Of The Soil

Mineral soils are broadly divided into solid materials and pore spaces. The solid materials are further divided into mineral matter and organic matter, while the pore spaces are made up of air and water. Therefore the four major components of the soil are:

Factors Of Soil Formation

Five variables influence the formation and development of soils. These five variables are the factors of soil formation. They include climate of a region, living organisms, relief (topography), parent material and time. These variables are interdependent in that all the

Origin and Formation of Soil

Scientifically, soil is derived from rocks through a variety of physical, chemical and biological processes. These processes are known as weathering. The soils so formed bear resemblance, especially in their chemical make-up, to the rocks from which they originate.

Definition of Soil

Soil, which is the solid part of the earth's surface, is the major element of land. Through physical, chemical and biological processes, soil is derived from rocks. Although soil originates from rocks, it is essentially different from them in certain respects.