Soil is a complex amalgum that, of necessity, has been defined from a variety of perspectives. It has been defined as: the unconsolidated mineral or organic material on the immediate surface of the Earth that serves as a natural medium for the growth of land plants; the unconsolidated mineral or organic matter on the surface of the Earth that has been subjected to and shows effects of such genetic and environmental factors as climate (including water and temperature effects), and macro- and microorganisms—conditioned by relief—acting on parent material over a period of time. A product-soil differs from the material from which it is derived in many physical, chemical, biological, and morphological properties and characteristics.
Additionally, soil has been defined as a natural body comprised of solids (minerals and organic matter), liquid, and gases that occurs on the land surface, occupies space, and is characterized by one or both of the following: horizons, or layers, that are distinguishable from the initial material as a result of additions, losses, transfers, and transformations of energy and matter; or the ability to support rooted plants in a natural environment.
Also, the upper limit of soil is the boundary between soil and air, shallow water, live plants, or plant materials that have not begun to decompose. Areas are not considered to have soil if the surface is permanently covered by water too deep (typically more than 2.5 meters) for the growth of rooted plants.
The lower boundary that separates soil from the nonsoil underneath is most difficult to define. Soil consists of horizons near the Earth's surface that, in contrast to the underlying parent material, have been altered by the interactions of climate, relief, and living organisms over time. Commonly, soil grades at its lower boundary to hard rock or to earthy materials virtually devoid of animals, roots, or other marks of biological activity. For purposes of classification, the lower boundary of soil is arbitrarily set at 200 cm.
The Burnt Cape is a limestone barren headland on the extreme northwest of the Northern Peninsula of Newfoundland, Canada. The prevailing harsh cold climate and calcareousSoils which are high in limestone content...
Lebônê Dirt-Powered Battery
500 million people in Africa live without power.
How does it work: Ordinary soil contains large number of ...
Extraterrestrial soilsLast Updated on 2013-05-20 at 04:04
Extraterrestrial soils may be defined as any of the solid granular crustal features of planets and moon other than those soils on planet Earth. Despite four decades of space... More »
Soil erosion and depositionLast Updated on 2013-03-29 at 16:52
Erosion is defined as the removal of soil, sediment, regolith, and rock fragments from the landscape. Most landscapes show obvious evidence of erosion.... More »
SoilLast Updated on 2013-02-21 at 12:47
An important factor influencing the productivity of our planet's various ecosystems is the nature of their soils. Soils are vital for the existence... More »
Surface runoffLast Updated on 2012-09-24 at 15:38
Surface runoff is a term used to describe when soil is infiltrated to full capacity and excess water, from rain, snowmelt, or other sources flow over... More »
Mt. St. Helena Flows and ValleysLast Updated on 2012-09-16 at 23:55
The Mt.St.Helena Flows and Valleys subsection is on the northwest trending Sonoma, Mayacamas, and Howell Ranges that are dominated by the Sonoma volcanics, and the valleys of... More »
Flooding of municipal solid waste landfillsLast Updated on 2012-08-31 at 10:59
Flooding of municipal solid waste landfills is an environmental risk for the long term worldwide. Municipal solid waste (MSW) landfills pose a number of other environmental... More »