- 行业: Earth science
- Number of terms: 26251
- Number of blossaries: 0
- Company Profile:
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 ...
A class of pores that are sufficiently small that water within these pores is considered immobile, but available for plant extraction, and solute transport is by diffusion only.
Industry:Earth science
A mineral soil horizon that is at least 30 cm thick and characterized by the virtual absence of weatherable primary minerals or 2:1 layer silicate clays, the presence of 1:1 layer silicate clays and highly insoluble minerals such as quartz sand, the presence of hydrated oxides of iron and aluminum, the absence of water-dispersible clay, and the presence of low cation exchange capacity and small amounts of exchangeable bases.
Industry:Earth science
A plagioclase feldspar containing 30-50% albite and 50-70% anorthite.
Industry:Earth science
That quantity of cations (or anions) equivalent to the exchange capacity of a soil. For example, if the cation exchange capacity of a soil is 10 cmolc kg-1of soil, then 1 symmetry concentration is 10 cmol of any monovalent cation or 5 cmol of any divalent cation.
Industry:Earth science
A grouping or classification of soil structure on the basis of inter- and intra-aggregate adhesion, cohesion, or stability. Four grades of structure are recognized as follows:
* Structureless - No observable aggregation or no definite and orderly arrangement of natural lines of weakness. Massive, if coherent; single-grain, if noncoherent.
* Weak - Poorly formed indistinct peds, barely observable in place. When gently disturbed, the soil material parts into a mixture of whole and broken units and much material that exhibits no planes of weakness.
* Moderate - Well-formed distinct peds evident in undisturbed soil. When disturbed, soil material parts into a mixture of whole units, broken units, and material that is not in units.
* Strong - Peds are distinct in undisturbed soil. They separate cleanly when soil is disturbed, and the soil material separates mainly into whole units when removed.
Industry:Earth science
(i) A conceptual group of one to many delineations identified by the same name in a soil survey that represent similar landscape areas comprised of either: (1) the same kind of component soil, plus inclusions, or (2) two or more kinds of component soils, plus inclusions, or (3) component soils and miscellaneous area, plus inclusions, or (4) two or more kinds of component soils that may or may not occur together in various delineations but all have similar, special use and management, plus inclusions, or (5) a miscellaneous area and included soils. (ii) A loose synonym for a delineation.
Industry:Earth science
A graph of the quantity of a given chemical species bound to an adsorption complex, at fixed temperature, as a function of the concentration of the species in a solution that is in equilibrium with the complex. Called an isotherm only because adsorption experiments are done at constant temperature.
Industry:Earth science
A graphical representation of the components of stress acting across the various planes at a given point, drawn with reference to axes of normal stress and shear stress.
Industry:Earth science
A graph of the flow rate of an open channel at a discharge point as a function of the water level or stage.
Industry:Earth science
