Glossary of Soil Science Terms - Browse
K-selected In ecological theory, that group of microorganisms in soil living at or near the carrying capacity of the soil environment. Analogous to autochthonous microorganisms.
K2O
Potassium oxide, designation on the fertilizer label that denotes the percentage of available potassium reported as K2O. Compare potash.
kame A low mound, knob, hummock, or short irregular ridge, composed of stratified sand and gravel deposited by a subglacial stream as a fan or delta at the margin of a melting glacier; by a supraglacial stream in a low place or hole on the surface of the glacier; or as a ponded deposit on the surface or at the margin of stagnant ice ( Jackson, 1997). Compare crevasse filling, kame moraine, kame terrace, esker, outwash.
kame moraine (a) An end moraine that contains numerous kames. (b) A group of kames along the front of a stagnant glacier, commonly comprising the slumped or erosional remnants of a formerly continuous outwash plain built up over the foot of rapidly wasting or stagnant ice ( Jackson, 1997).
kame terrace A terrace-like ridge or bench consisting of stratified sand and gravel (i) deposited by a meltwater stream flowing between a melting glacier and a higher valley wall or lateral moraine, and (ii) left standing after the disappearance of the ice. It is commonly pitted with “kettles” and has an irregular ice-contact slope (Hawley and Parsons, 1980).
kaolinite A clay mineral of the kaolin subgroup. It has a 1:1 layer structure composed of shared sheets of Si-O tetrahedrons and Al-(O,OH) octahedrons with very little isomorphous substitution. Compare Appendix I, Table A3.
karren Repeating, surficial solution channels, grooves or other forms etched onto massive, bare limestone surfaces; types range in depth from a few millimeters to >1 m and separated by ridges; the total complex (all varieties) of surficial solution forms found on compact.
karst A kind of topography formed in limestone, gypsum, or other rocks by dissolution that is characterized by closed depressions, sinkholes, caves, and underground drainage. Various types of karst can be recognized depending upon the dominant surface features: karst dominated by closed depressions (sinkhole karst – temperate climates; cockpit karst – humid tropical climates), closed depressions and large rivers (fluviokarst), bare rock dominated by dissolution joints (pavement karst), tropical cone-, toweror domed-hills (kegel karst), or karst thinly mantled with glacial drift (glaciokarst), etc. (Schoeneberger and Wysocki, personal communication, 2013; White, 1988).
karst cone A conically-shaped residual hill in karst with a rounded top and relatively steep, convex (e.g., parabolic) side slopes, commonly in tropical climates (Schoeneberger and Wysocki, personal communication, 2013; White, 1988). Compare karst tower, mogote.
karst drainage pattern A drainage pattern that lacks an integrated drainage system associated with soluble rocks with little or no surface drainage but a considerable underground, internal drainage system; characteristic of karst landscapes underlain by limestone, gypsum, or salt (Schoeneberger and Wysocki, personal communication, 2013).
karst tower An isolated, separate hill or ridge in a karst region consisting of an erosional remnant of limestone or other sedimentary rocks with vertical or near-vertical, convex side slopes and commonly surrounded by an alluvial plain, lagoon, or deep rugged ravines (Schoeneberger and Wysocki, personal communication, 2013). Compare mogote, karst cone.
karst valley A closed depression formed by the coalescence of multiple sinkholes; an elongate, solutional valley. Its drainage is subsurface, diameters range from several hundred meters to a few kilometers, and it usually has a scalloped margin inherited from the sinkholes. It may have nominal, local channel flow (small streams), sequential sinkhole inlets (springs) and outlets (swallow hole, etc.); also called compound sinkhole (not preferred), uvala (not preferred; Schoeneberger and Wysocki, personal communication, 2013; Jackson, 1997). Compare sinkhole, interior valley.
karstic (adjective) Having the attributes of karst (Schoeneberger and Wysocki, personal communication, 2013; Jackson, 1997).
karstic marine terrace A relict, wave-cut terrace or solution platform formed across soluble bedrock (e.g., limestone), and subsequently subaerially weathered by solution resulting in prominent karst features (e.g., sinkholes, karst valleys, solution pipes, etc.); a type of marine terrace, extensive across the Florida peninsula. Dunefields and sand sheets of reworked coastal/ fluviomarine sands are common capping materials (Schoeneberger and Wysocki, personal communication, 2013).
karstland (not preferred; use karst). A landscape dominated by dissolution features (e.g., sinkhole, blind valley, closed depressions, underground drainage) formed in soluble rocks (Schoeneberger and Wysocki, personal communication, 2013; Jackson, 1997).
Kd
Refer to distribution coefficient, Kd.
kegel karst A general name used to describe several types of humid tropical karst landscapes characterized by numerous, closely spaced cone(cone karst), hemispherical (halbkugelkarst), or tower-shaped (tower karst) hills with vertical or near-vertical walls and having intervening closed depressions and narrow steep-walled karst valleys or passageways (Schoeneberger and Wysocki, personal communication, 2013; Jackson, 1997). Compare cockpit karst.
kettle A steep-sided, bowl-shaped depression commonly without surface drainage (closed depression) in drift deposits, often containing a lake or swamp, and formed by the melting of a large, detached block of stagnant ice that had been wholly or partly buried in the drift. Kettles range in depth from 1 to tens of meters, and with diameters up to 13 km ( Jackson, 1997). Compare pothole.
kinetic energy Energy due to motion and is proportional to the velocity squared.
kipuka A low “island” of land surrounded by a younger (more recent) lava flow (MacDonald and Abbott, 1970). Compare steptoe.
kluftkarren (not preferred) refer to solution fissure.
knickpoint (a) A point of abrupt inflection in the longitudinal profile of a stream or of its valley (e.g., a waterfall); it marks the maximum headward erosion of a new erosion cycle that grades to a new, lower base level; (b) Any interruption or break in slope (Schoeneberger and Wysocki, personal communication, 2013).
knob (a) A rounded eminence, a small hill or mountain; especially a prominent or isolated hill with steep sides, commonly found in the Southern United States.(b) A peak or other projection from the top of a hill or mountain. Also, a boulder or group of boulders or an area of resistant rocks protruding from the side of a hill or mountain ( Jackson, 1997). Compare stack [geom].
knoll A small, low, rounded hill rising above adjacent landforms (Hawley and Parsons, 1980).
kriging A statistical method based on the theory of regionalized variables for predicting without bias and minimum variance the spatial distribution of earth components, including soil properties.
krotovina Irregular tubular streaks within one layer of material transported from another layer by filling of tunnels made by burrowing animals with material from outside the layer in which they are found.