Topsoil is the upper, outermost layer of soil Soil is a natural body consisting of layers 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, usually the top 2 inches (5.1 cm) to 8 inches (20 cm). It has the highest concentration of organic matter Organic matter is matter that has come from a once-living organism; is capable of decay, or the product of decay; or is composed of organic compounds. The definition of organic matter varies upon the subject it is being used for and microorganisms A microorganism or microbe is an organism that is microscopic (too small to be seen by the naked human eye). The study of microorganisms is called microbiology, a subject that began with Anton van Leeuwenhoek's discovery of microorganisms in 1675, using a microscope of his own design and is where most of the Earth Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets. It is sometimes referred to as the World, the Blue Planet,[note 6] or by its Latin name, Terra.[note 7]'s biological Biology is a natural science concerned with the study of life and living organisms, including their structure, function, growth, origin, evolution, distribution, and taxonomy soil activity occurs.
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Importance
Plants Plants are living organisms belonging to the kingdom Plantae. They include familiar organisms such as trees, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The scientific study of plants, known as botany, has identified about 350,000 extant species of plants, defined as seed plants, bryophytes, ferns and fern allies. As of 2004, generally concentrate their roots In vascular plants, the root is the organ of a plant that typically lies below the surface of the soil. This is not always the case, however, since a root can also be aerial or aerating (growing up above the ground or especially above water). Furthermore, a stem normally occurring below ground is not exceptional either (see rhizome). So, it is in and obtain most of their nutrients A nutrient is a chemical that an organism needs to live and grow or a substance used in an organism's metabolism which must be taken in from its environment. Nutrients are the substances that enrich the body. They build and repair tissues, give heat and energy, and regulate body processes. Methods for nutrient intake vary, with animals and from this layer. The actual depth of the topsoil layer can be measured as the depth from the surface to the first densely packed soil layer known as subsoil Subsoil is the layer of soil under the topsoil on the surface of the ground. The subsoil may include substances such as clay and/or sand that has only been partially broken down by air, sunlight, water, wind etc., to produce true soil. Below the subsoil is the substratum, which can be residual tobol, sediments, or aeolian deposits, largely.
Classification
In soil classification systems, topsoil is known as the "A Horizon," A soil horizon is a specific layer in the land area which measures parallel to the soil surface and possesses physical characteristics which differ from the layers above and beneath. Horizon formation is a function of a range of geological, chemical, and biological processes and occurs over long time periods. Soils vary in the degree to which therefore, it is the very top layer.[1]
Commercial application
A variety of soil mixtures are sold commercially Commerce is a division of trade or production which deals with the exchange of goods and services from producer to final consumer OR commerce is the exchange of goods and services from the point of production to the point of consumption to satisfy human wants. It comprises the trading of something of economic value such as goods, services, as topsoil, usually for use in improving gardens A garden is a planned space, usually outdoors, set aside for the display, cultivation, and enjoyment of plants and other forms of nature. The garden can incorporate both natural and man-made materials. The most common form today is known as a residential garden, but the term garden has traditionally been a more general one. Zoos, which display and lawns A lawn is an area of aesthetic and recreational land planted with grasses or other low durable plants, which usually are maintained at a lower and consistent height. Low ornamental meadows in natural landscaping styles are a contemporary option of a lawn. In recreational contexts, the specialised names turf, pitch, field or green may be used,, (e.g. container gardens Container gardening is the practice of growing plants exclusively in containers instead of planting them in the ground. Pots, traditionally made of terracotta but now more commonly plastic, and windowboxes have been the most commonly seen. Small pots are commonly called flowerpots. In some cases, this method of growing is used for ornamental, potting soil).
Erosion
A major environmental concern known as topsoil erosion Erosion is the process of weathering and transport of solids in the natural environment or their source and deposits them elsewhere. It usually occurs due to transport by wind, water, or ice; by down-slope creep of soil and other material under the force of gravity; or by living organisms, such as burrowing animals, in the case of bioerosion occurs when the topsoil layer is blown or washed away. Without topsoil, little plant life is possible. The estimated annual costs of public and environmental health losses related to soil erosion exceed $45 billion. [2] Conventional agriculture encourages the depletion of topsoil because the soil must be plowed and replanted each year. Sustainable techniques attempt to slow erosion through the use of cover crops in order to build organic matter in the soil. The United States alone loses 2 billion tons of topsoil per year. This is of great ecological concern as one inch of topsoil can take 500 years to form naturally.[3]
See also
- Agricultural wastewater
- Desertfication
- Dust bowl The Dust Bowl or the Dirty Thirties was a period of severe dust storms causing major ecological and agricultural damage to American and Canadian prairie lands from 1930 to 1936 . The phenomenon was caused by severe drought coupled with decades of extensive farming without crop rotation, fallow fields, cover crops or other techniques to prevent
- Erosion control Erosion control is the practice of preventing or controlling wind or water erosion in agriculture, land development and construction. Effective erosion controls are important techniques in preventing water pollution and soil loss
- No-till farming No-till farming is a way of growing crops from year to year without disturbing the soil through tillage. No-till is an emergent agricultural technique which can increase the amount of water in the soil and decrease erosion. It may also increase the amount and variety of life in and on the soil but may require increased herbicide usage
- Nonpoint source pollution Nonpoint source pollution is water pollution affecting a water body from diffuse sources, such as polluted runoff from agricultural areas draining into a river, or wind-borne debris blowing out to sea. Nonpoint source pollution can be contrasted with point source pollution, where discharges occur to a body of water at a single location, such as
- Sustainable agriculture Sustainable agriculture uses ecological principles to farm, hence the prefex agro- to farm and ecology- the science of the relationship between organisms and their environment. It has been defined as "an integrated system of plant and animal production practices having a site-specific application that will, over the long term:
- Waterway degradation
References
- ^ U.S. Department of Agriculture (USDA), Soil Survey Division Staff (1993). "Soil Survey Manual." USDA Handbook 18. Chapter 3.
- ^ http://www.ce.cmu.edu/~gdrg/readings/2007/02/20/Pimental_EnvironmentalEnergeticAndEconomicComparisonsOfOrganicAndConventionalFarmingSystems.pdf
- ^ http://discovermagazine.com/2001/may/feateatlocal
- The lowdown on topsoil: It's disappearing
- Mann, C (2008). "Our Good Earth". National Geographic Magazine National Geographic, formerly the National Geographic Magazine, is the official journal of the National Geographic Society. It published its first issue in 1888, just nine months after the Society itself was founded. It is immediately identifiable by the characteristic yellow frame that surrounds its front cover 214 (3): 80–107. http://ngm.nationalgeographic.com/2008/09/soil/mann-text.
External links
- USDA Electronic Field Office Technical Guide - Detailed soil conservation guides tailored to individual states/counties
- UK British Topsoil Suppliers Association - Detailed soil information guides
Categories: Soil Categories: Granular materials | Natural materials | Natural resources | Agriculture | Horticulture and gardening Horticulture and gardening involves cultivating fruits, vegetables, flowers, or ornamental plants in a public or domestic garden. It is a sub-set of agriculture | Soil improvers | Lawn care Categories: Landscape architecture | Horticulture and gardening | Lawns | Types of soil
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High Plains Journal
The topsoil had been generated through the millennia, and it was rich. All you had to do was plow it. That was a formidable task and one that should never ...
