fragipan


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fragipan

[′fraj·ə‚pan]
(geology)
A dense, natural subsurface layer of hard soil with relatively slow permeability to water, mostly because of its extreme density or compactness rather than its high clay content or cementation.
References in periodicals archive ?
Also, high concentrations of soluble N can occur at the soil surface when there is a soil horizon barrier (e.g., Fragipan) present in the soil profile that results in return flow of leached N back to the soil surface (Lehman and Ahuja 1985; Smith et al.
Except for the fragipan soils, the C horizons of these soils were friable when moist and slightly hard when dry (Table 2).
A functional soil site assessment must include a detailed description of the soil horizons on a depth basis for the following soil properties: texture; structure; color; redoximorphic features (mottles) to summarize the limitations to a restrictive layer (bedrock, fragipan, etc.), water table, or inadequate treatment capacity.
The soil was a Tokomaru silt loam, classified as a Typic Fragiaqualf (Soil Taxonomy 1975), which consisted of a silt loam A horizon (0-0.25 m) over a clay loam B horizon (0.25-0.8 m) over a very compact silt loam C horizon with a fragipan. The drainage from each paddock was measured continuously using 30 [degrees] V-notch weirs and ISCO flow meters (model 2310).
The Grenada series (fine-silty, mixed, active thermic Glossic Fragiudalf) consists of moderately well drained soils that have a fragipan. These soils formed in loessal material on uplands and terraces.
Soils in the Catskills are generally permeable relative to rainfall intensity and underlain by a shallow, low permeable, restrictive layer, typically bedrock or fragipan. Rainwater easily permeates the soil and, by-and-large, runs laterally on top of the restrictive layer downslope; this is typically called interflow.
The soils on the study area were derived from loess (Memphis, Grenada, Loring series), had 2 to 6% slopes, and frequently contained a fragipan subsurface horizon.
The Grenada series consists of moderately well drained soils that have a fragipan. These soils formed in loessal material on uplands and terraces.
The research project was initiated originally to determine the effects of erosion on the productivity and erodibility of fragipan soils in the lower Mississippi River Valley.
(1990, 1991) used the depth to a fragipan (Bx) in loess to estimate the relative amount of erosion.
These include solum depth (17), content and distribution of clay in the B horizon (28), depth to the argillic horizon (26,32), depth to fragipan (10,38,44,45), and depth to the bottom of argillic horizons and layers containing accumulations TABULAR DATA OMITTED of elements with high atomic mass, such as iron (4,40,41).