mollisol


mollisol
/mol"euh sawl', -sol'/, n.
a productive agricultural soil common to the world's grasslands, characterized by a dark surface layer rich in organic matter. Cf. brown soils.
[1970-75; < L molli(s) soft + -SOL]

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▪ soil type
 one of the 12 soil orders in the U.S. Soil Taxonomy (soil). Mollisols are characterized by a significant accumulation of humus in the surface horizon, or uppermost layer, which is almost always formed under native grass vegetation. They are highly arable soils used principally for growing grain and cereal crops, often inspiring the name “breadbasket” for the regions where they dominate. Covering approximately 6 percent of the nonpolar continental land area on Earth, they are found primarily in subhumid to semiarid grasslands in Europe, Asia, the Argentine Pampa, the Great Plains of North America, and the Palouse region of the northwestern United States.

      The important mineral nutrients—calcium, magnesium, potassium, and sodium—are found through most, if not all, layers of the Mollisol soil profile. Below the surface horizon, Mollisols do not show major accumulations of humus or translocated (migrated) aluminum- and iron-bearing minerals. The uppermost zone has a characteristic dark colour, making for a striking profile and giving clear evidence of the decomposition of grass roots and of the wet-dry cycles over millennia that are essential to the formation of these soils.

      Mollisols differ from Alfisols (Alfisol) (another important agricultural soil) by their higher humus content, from Vertisols (Vertisol) (another soil of grassland origin) by their lack of cracking or swelling, and from Ultisols (Ultisol) (like Mollisols, a humus-rich soil) by their greater retention of available metal nutrients.

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Universalium. 2010.

Look at other dictionaries:

  • mollisol — MOLLISÓL s. (geogr.) merzlotă. (mollisol din zona polară.) [var. (după alte surse) molisol]. Trimis de siveco, 13.09.2007. Sursa: Sinonime …   Dicționar Român

  • Mollisol — Als Mollisole bezeichnet man gemäß der USDA Bodenklassifikation leicht saure Böden der gemäßigten Breiten, die von Gräsern (Poaceae) bewachsen sind. Sie finden sich in der argentinischen Pampa, den Prärien des mittleren Westen der USA und den …   Deutsch Wikipedia

  • mollisol — ● mollisol nom masculin Partie superficielle du sol, qui dégèle en été, sous un pergélisol …   Encyclopédie Universelle

  • Mollisol —   [zu lateinisch mollis »weich«, »locker« und russisch zola »Asche«] der, s, Bodentyp der amerikanischen Bodensystematik mit mächtigem, dunklem, humusreichem, krümeligem A Horizont. Dazu gehören die Tschernoseme u. a. Steppenböden …   Universal-Lexikon

  • Mollisol — La exactitud de la información en este artículo o sección está discutida. En la página de discusión puedes consultar el debate al respecto. En pedología (estudio de suelos), mollisol es la capa de hielo superficial del permafrost. Se encuentra en …   Wikipedia Español

  • Mollisol — Le mollisol désigne la partie du sol qui gèle en hiver et dégèle en été. Les Mollisols sont une présentation des sols dans la taxinomie pédologique des États Unis. Ils se forment dans des régions semi arides à semi humides, habituellement sous un …   Wikipédia en Français

  • mollisol — noun A type of soil that forms in semiarid to semihumid areas, typically under a grassland cover, with deep, high organic matter and a nutrient enriched surface soil (or horizon) …   Wiktionary

  • mollisol —    A soil layer subject annual thawing and freezing, often becoming mobile upon thawing [16] …   Lexicon of Cave and Karst Terminology

  • Mollisol — Mol|li|sol der; s <zu lat. mollis »weich, locker« u. russ. zola »Asche«> Bodentyp der amerik. Bodensystematik mit mächtigem, dunklem, humusreichem, krümeligem Oberboden (z. B. ↑Tschernosem u. Steppenboden) …   Das große Fremdwörterbuch

  • mollisol — n. mineral rich surface layer soil …   English contemporary dictionary


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