Soil

SOIL

Soil (sometimes called dirt) is the combination of rock, mineral fragments (pieces), organic matter (dead and living things), water and air.
It is mostly made up of grains of rock (weathered by wind, rain, sun, snow) andhumus. The type of soil depends on the mix of humus and on the size of the grains of the rock. The grains can be very small and smooth, such as clay, or they can be larger, like grains of sand or even a piece of gravel.  Soils are important to our ecosystem for six main reasons: first, soils are a place for plants to grow; second, soils control the speed and the purity of water that moves through them; third, soils recycle nutrients from dead animals and plants; fourth, soils change the air that surrounds the earth, called theatmosphere; fifth, soils are a place to live for animals, insects and very small living things called micro-organisms; sixth, soils are the oldest and the most used building materials. The climate is very important when soil is made. Soil from different climates can have very different qualities the type of soil varies from.

The word Soil is derived from Latin word “Solum” which means earthy materials in which plants grows.
The science which deals with the study of soil is called “Pedology” or “Edaphology”. It is defined as an unconsolidated layer, formed from lithological – varying rocks by weathering agencies which is modified by many organic and biochemical processes.
Soil Profile:
A soil consists of three horizontal layers. They are true soil at the top, sub soil and bedrock. Each horizon is different from other by its own physical and chemical composition and organic contents produced during the process of soil formation.

 Soil Texture:
Soil texture refers to the mixture of different soil particles grading from coarse into fine grades of gravel, sand, silt and clay. Soil with a large proportion of sand grains are called Sandy Soils. Clayey Soils have a large proportion of clay particles and a little of...