- 産業: Earth science
- Number of terms: 26251
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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 ...
A series of relatively high-molecular-weight, yellow to black colored organic substances formed by secondary synthesis reactions in soils. The term is used in a generic sense to describe the colored material or its fractions obtained on the basis of solubility characteristics. These materials are distinctive to soil environments in that they are dissimilar to the biopolymers of microorganisms and higher plants (including lignin).
Industry:Earth science
A coarse-grained, basic igneous rock similar in mineral composition to basalt.
Industry:Earth science
A soil that possesses properties and distinguishing characteristics of two or more separate soils.
Industry:Earth science
A plant nutrient found at relatively high concentrations ( >500 mg kg-1) in plants. Usually refers to N, P, and K, but may include Ca, Mg, and S.
Industry:Earth science
(i) That portion of the micro flora presumed to subsist on the more resistant soil organic matter and little affected by the addition of fresh organic materials. (ii) Microorganisms indigenous to a given ecosystem; the true inhabitants of an ecosystem; referring to the common microbiota of the body of soil microorganisms that tend to remain constant despite constant fluctuations in the quantity of fermentable organic matter.
Industry:Earth science
A representative sample taken from an area, a field, or portion of a field from which the physical, biological, and chemical properties can be determined.
Industry:Earth science
(i) A dimensionless measure of the deviation of the chemical potential of a substance from its value at a standard state. It is defined by the equation: µ = µ°+ RT ln a, where µ is the chemical potential at activity = a, µ°is the chemical potential in the standard state (where a = 1. 0), R is the molar gas constant, and T is the absolute temperature. In solution a = molal concentration at infinite dilution (molal concentration = molar concentration at low concentrations), and in gases a = partial pressure in atmospheres. (ii) Informally, in solution, it may be taken as the effective concentration of a substance.
Industry:Earth science
A Fe-rich dioctahedral mica with tetrahedral Al (or Fe3+) usually greater than 0. 2 atoms per formula unit and octahedral R3+ correspondingly greater than 1. 2 atoms. A generalized formula is K(R1. 333+R0. 672+)(Si3. 67Al0. 33)O10(OH)2 with Fe3+>>Al and Mg>Fe(II) (unless altered). Further characteristics are d(060) >0. 151 nm and (usually) broader infrared spectra than celadonite. Mixtures containing an iron-rich mica as a major component can be called glauconitic.
Industry:Earth science
A highly charged, averages about 159 cmolckg-1 for soil vermiculites but has a very wide range, layer silicate of the 2:1 type that is formed from mica. It is characterized by adsorption preference for potassium, ammonium, and cesium over smaller exchange cations. It may be di- or trioctahedral.
Industry:Earth science
A soil whose properties are believed to be sufficiently different from other known soils to justify a new series name but comprising such a limited geographic area that creation of a new series is not justified. Use of this term was discontinued in 1988.
Industry:Earth science
