Topsoil


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topsoil

[′täp‚sȯil]
(geology)
Soil presumed to be fertile and used to cover areas of special planting.
Surface soil, usually corresponding with the A horizon, as distinguished from subsoil.

Topsoil

 

the surface layer of soil that is regularly worked by tillage equipment. Topsoil 20–22 cm deep is considered normal. If it is less than 20 cm deep, it is considered shallow; if it is 22–35 cm or greater in depth it is considered deep. Between 80 and 90 percent of the roots of cultivated plants is concentrated in the topsoil. Therefore, the soil must be fertile, containing adequate amounts of the nutrients, moisture, and oxygen needed for both the roots and the soil microorganisms that break down organic remains into compounds assimilable by the plants. Organic and inorganic fertilizers are applied to the topsoil to enrich it with nutrients. The soil is loosened to increase its absorption of precipitation and its oxygen content.

topsoil

1. The surface of upper layer of soil, as distinct from the subsoil; usually contains organic matter.
2.See loam.
References in periodicals archive ?
To see what can happen to civilizations that lost the topsoil they needed to grow food, look no further than Syria or Libya.
The lowest values of richness were found in FF2-UT (litter standing stock) and FF2-MT (topsoil), while higher values occurred in FF4-UT (litter standing stock), FF4-LT (topsoil) and FF1-MT (litter standing stock) (Table 1).
When rainfall occurs, overland water flow can transport sediments from the upper to lower slope positions; meanwhile, it also infiltrates from the topsoil layer to the deeper soil layer with the eluviation of CaC[O.sub.3] (Schlesinger and Pilmanis 1998; Tan et al.
An approximate depth of 0.15 m of topsoil was then added to the topsoil subplots.
It makes sense to purchase a load of topsoil to supplement what the builders sprinkled across the site before they fled, or as a booster for exhausted soil.
* The second component of EarthGuard Fusion is Terra Novo's hydraulically-applied topsoil replacement, EarthGuard Organix.
If the topsoil is suffering from compaction it can inhibit root growth and nutrient uptake causing nutrient deficiency leading to a loss of yield.
Unless you are blessed with deep, fertile topsoil, sooner or later you will want to physically merge enriched topsoil with impoverished subsoil.
Clark warns that playing in topsoil, as in this photo, has risks: "Topsoil can contain bacteria, mold, insecticides, and pesticides that can cause dangerous infections and have toxic effects.
Abi Culley, environmental project officer for Building Sustainable Neighbourhoods, said: "This topsoil gives the project a springing start.
At British Sugar's Wissington plant in Norfolk, the topsoil site is located over 1 1/2 miles from the central weighbridge and handles over 50,000t of topsoil per year either loaded onto trucks or as a bagged product.
Dandy's Topsoil, based in Sealand, has bought H&M Taylor Coal Merchants, operating from Heswall and Connah's Quay, for a five figure sum, safeguarding two jobs.