spodic horizon

spodic horizon

[′späd·ik hə′rīz·ən]
(geology)
A soil horizon characterized by illuviation of amorphous substances.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
One of the Podzols is on the upper slope and has a dominant E horizon; the other is on the footslope and has a dominant spodic horizon. Mean air temperature is 6.5[degrees]C, and mean annual precipitation is 1935 mm (Sommer 2002).
The spodic horizon represents an accumulation of illuviated organic matter and iron and aluminum oxides lying underneath a bleached horizon.
The process was especially intensive (11.6 mg [m.sup.-2] [yr.sup.-1]) per centimetre in the spodic horizon and only a little slower (10.1 mg [m.sup.-2] [yr.sup.-1] [cm.sup.-1]) in the ochric epipedon.
On the top horizon, under the leaf litter and humus, the acids resulting from organic matter decomposition alter clay intensively and the resulting products accumulate further down, making a spodic horizon rich in sesquioxides and humic compounds.
If the topsoil is thinned by erosion, the spodic horizon may be mixed into the topsoil by tillage.
Spodosols, soils that form beneath cool, wet, coniferous forests, have a unique feature called a spodic horizon in which SOM increases.
Frequently, the Cryorthents show podzolic features (Table 2, D2) without fitting the definition of a spodic horizon (Beyer et al.
Spodosols have a pronounced spodic horizon where iron, aluminum, and organic matter have accumulated.
The soil is characterized by a sandy texture and represents a Podzol with well-expressed spodic horizons of yellow-ocherous tones underlying albic horizons that were affected by the fire.
A previous study reported that the soil development grades from undifferentiated parent material at the Lake Michigan shoreline to soils with well-defined albic and spodic horizons (Lichter 1998a).
The mass ratios of OC to iron (OC:Fe) of the extracts in some low pH, organic samples (e.g., spodic horizons) implied the presence of organo-iron complexes rather than adsorbed forms.