- 行业: Earth science
- Number of terms: 26251
- Number of blossaries: 0
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An international scientific society that fosters the transfer of knowledge and practices to sustain global soils. Based in Madison, WI, and founded in 1936, SSSA is the professional home for 6,000+ members dedicated to advancing the field of soil science. It provides information about soils in ...
Organic soils that have organic soil materials in more than half of the upper 80 cm, or that are of any thickness if overlying rock or fragmental materials that have interstices filled with organic soil materials. (An order in the U. S. system of soil taxonomy. )
Industry:Earth science
Phyllosilicate minerals have layer structures composed of shared octahedral and tetrahedral sheets.
* plane (of atoms) - A flat (planar) array of atoms of one atomic thickness. Example: plane of basal oxygen atoms within a tetrahedral sheet.
* sheet (of polyhedra) - Flat array of more than one atomic thickness and composed of one level of linked coordination polyhedra. A sheet is thicker than a plane and thinner than a layer. Example: tetrahedral sheet, octahedral sheet.
* layer - A combination of sheets in a 1:1 or 2:1 assemblage.
* interlayer - Materials between structural layers of minerals, including cations, hydrated cations, organic molecules, and hydroxide octahedral groups and sheets.
* unit structure - The total assembly of a layer plus interlayer material.
Industry:Earth science
Histosols that have a high content of undecomposed plant fibers and a bulk density less than about 0. 1 g cm-3. Fibrists are saturated with water for periods long enough to limit their use for most crops unless they are artificially drained.
Industry:Earth science
Mineral soils that have no distinct subsurface diagnostic horizons within 1 m of the soil surface. (An order in the U. S. system of soil taxonomy. )
Industry:Earth science
An association of mutual benefit to two or more species but without the cooperation being obligatory for their existence or the performance of some function.
Industry:Earth science
Fluorescence resulting from a reaction between a substance and a specific antibody that is bound to a fluorescent dye.
Industry:Earth science
Large pores responsible for preferntial flow and rapid, far-reaching transport.
Industry:Earth science
Potential envergy of soil water due to the attractive forces (adhesion and cohesion) between water and the soil matrix. Matric potential is expressed as energy per unit volume and equals the product of the height of rise in a capillary tube, hm, the water density, ρ, and the gravitational constant, g, (ρghm). Matric head is expressed as energy per weight and is equal to the height of rise ina capillary tube (hm).
Industry:Earth science
An organic soil in which the plant residues have been altered beyond recognition. The sum of the thicknesses of organic layers is usually greater than the sum of the thicknesses of mineral layers.
Industry:Earth science
