SOIL AND SOIL ENGINEERING -Definition of Soil.

SOIL AND SOIL ENGINEERING

Soils are one of Earth's essential natural resources, yet they are often taken for granted. Most people do not realize that soils are a living, breathing world supporting nearly all terrestrial life. Soils and the functions they play within an ecosystem vary greatly from one location to another as a result of many factors, including differences in climate, the animal and plant life living on them, the soil's parent material, the position of the soil on the landscape, and the age of the soil.

Scientists, engineers, farmers, developers and other professionals consider a soil's physical and chemical characteristics, moisture content and temperature to make decisions such as:

1. Where is the best place to build a building?
2. What types of crops will grow best in a particular field?
3. Will the basement of a house flood when it rains?
4. How can the quality of the groundwater in the area be improved?

Using the data collected in the GLOBE Soil Investigation, students help scientists describe soils and understand how they function. They determine how soils change and the ways they affect other parts of the ecosystem, such as the climate, vegetation, and hydrology. Information about soils is integrated with data from the other GLOBE protocol investigations to gain a better view of Earth as a system

Why Investigate Soils?

Soils develop on top of Earth's land surface as a thin layer, known as the pedospher e. This thin layer is a precious natural resource and so deeply affects every part of the ecosystem that it is often called the "great integrator." For example, soils hold nutrients and water for plants and animals. They filter and clean water that passes through them. They can change the chemistry of water and the amount that recharges the groundwater or returns to the atmosphere to form rain. The foods we eat and most of the materials we use for paper, buildings, and clothing are dependent on soils. Soils play an important role in the amount and types of gases in the atmosphere. They store and transfer heat, affect the temperature of the atmosphere, and control the activities of plants and other organisms living in the soil. By studying these functions that soil's play, students and scientists learn to interpret a site 's climate, geology, vegetation, hydrology, and human history. They begin to understand soil as an important component of every ecosystem on Earth.

Definition of Soil

The soil is at the interface between the atmosphere and lithosphere (the mantle of rocks making up the Earth's crust). It also has an interface with the hydrosphere, i.e. the sphere describing surface water, ground water and oceans. The soil sustains the growth of many plants and animals, and so forms part of the biosphere. A combination of physical, chemical and biotic forces acts on organic and weathered rock fragments to produce soils with a porous fabric that contain water and air (pedosphere). We consider soil as a natural body of mineral and organic material that is formed in response to many environmental factors and processes acting on and changing soil permanently.