- 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 positively charged ion held on or near the surface of a solid particle by a negative surface and which may be replaced by other positively charged ions in the soil solution. Usually expressed in centimoles or millimoles of charge per kilogram.
Industry:Earth science
A measure of the proportion of the aggregates in a soil which do not easily slake, crumble, or disintegrate.
Industry:Earth science
(i) A cemented concentration of a chemical compound, such as calcium carbonate or iron oxide, that can be removed from the soil intact and that has no orderly internal organization. (ii) (micromorphological) A glaebule with undifferentiated fabric. (iii) Specialized tissue enlargements, or swellings, on the roots, stems, or leaves of plants, such as are caused by nitrogen-fixing microorganisms.
Industry:Earth science
A sheet-like lag concentration of coarse fragments in surficial sediments. In cross section, the line may be marked only by scattered fragments or it may be a discrete layer of fragments. The fragments are more often pebbles or cobbles than stones. A stone line generally overlies material that was subject to weathering, soil formation, and erosion before deposition of the overlying material. Many stone lines seem to represent buried erosion pavements, originally formed by running water on the land surface and concurrently covered by surficial sediment.
Industry:Earth science
A man-made surface horizon more than 50 cm thick that is formed by long-continued manuring and mixing.
Industry:Earth science
A great soil group of the intrazonal order and hydromorphic suborder, consisting of soils with an organic mat on the surface over a very thin layer of acid humus material underlain by a whitish-gray leached layer, which may be as much as 2 or 3 feet in thickness, and is underlain by a brown, or very dark-brown, cemented hardpan layer; formed under various types of forest vegetation in cool to tropical, humid climates under conditions of poor drainage.
Industry:Earth science
A parameter that estimates the interaction between ions in solution. It is calculated as one-half the sum of the products of ionic concentration and the square of ionic charge for all the charged species in a solution. It is needed for calculation of single ion activity.
Industry:Earth science
A graphical representation of nutrient application rate or availability versus crop yield or nutrient uptake.
Industry:Earth science
