Thursday, January 20, 2011

Soil and its Uses

My son had an assignment in his Science subject.  They were asked to find out the important uses of soil.  To help out those of you who might be looking for the same, here's what we found:

Soil is a natural body consisting of layers (soil horizons) of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics.
It is composed of particles of broken rock that have been altered by chemical and environmental processes that include weathering and erosion. Soil differs from its parent rock due to interactions between the lithosphere, hydrosphere, atmosphere, and the biosphere.It is a mixture of mineral and organic constituents that are in solid, gaseous and aqueous states.

Uses of Soil:

1.       Soil is used in agriculture, where it serves as the primary nutrient base for the plants. Soil resources are critical to the environment, as well as to food and fiber production. Soil provides minerals and water to plants. Soil is used to make plants grow healthy.  The types of soil used in agriculture (among other things, such as the purported level of moisture in the soil) vary with respect to the species of plants that are cultivated.

2.       Soil is used in constructions and arts. Soil material is a critical component in the mining and construction industries. Soil serves as a foundation for most construction projects. Massive volumes of soil can be involved in surface mining, road building, and dam construction. Earth sheltering is the architectural practice of using soil for external thermal mass against building walls.  Soil is used to make pots.

3.       Soil play an important role in filtrating and purifying water. After coming down as precipitation, much of the rain water is percolated through the many horizons of a soil profile and renamed as groundwater. As the water moves through different areas such as wetlands, forests, and riparian zones many pollutants are removed. Pollutants such as viruses, oils, metals, excess nutrients, and sediments are filtered out by the soil and surrounding organisms.

4.       Waste management often has a soil component. Landfills use soil for daily cover.  Septic drain fields treat septic tank effluent using aerobic soil processes.

5.       Organic soils, especially peat, serve as a significant fuel resource.

Source:  Google