Soils Ch 3
A soil pedon is
A three-demensional unit that embodies the primary characteristics of an individual soil
Argillic horizons are characterized by
Accumulation of silicate clays
A soil likely to contain a significant content of low activity clays is
An Ultisol in the Congo River basin in Africa
What soil moisture regime has the highest soil moisture levels?
Aquic
A pedon is a 3 dimensional field unit occupying about 1000 square meters (1 hectare) is land area.
False
For agriculture use in a given region, a soil with an ochric epipedon could generally be expected to be more productive than one with a Millicent epipedon.
False
If the soils are to be used for crop production, for which soil order would land drainage be most critical?
Histosols
In which epipedon is the organic matter level generally lowest?
Ochric
The categories of soil taxonomy from first to last is
Order, Suborder, Great Group, Subgroup, Family, Series
Which subsurface diagnostic horizon would you expect to find in a highly weathered soil of the humid tropics?
Oxic
The map units on a detailed soil map in a county soil survey report are most likely to be labeled with names from which category of soil taxonomy?
Series
Soils in this order are commonly sandy in texture, quite acidic and develop primarily under coniferous trees in cool to cold climates
Spodosols
A polypedon or individual soil is a group of closely related pedons that conceptually approximates what in the United States is called a soil series.
True
An aquic soil moisture regime connotes a higher degree of soil moisture saturation than an ustic one.
True
An argillic horizon is a diagnostic horizon characterized by the subsurface accumulation of silicate clays.
True
Andisols are found mostly near recently active volcanoes.
True
Histosols generally have higher organic matter contents than Mollisols.
True
Mollisols are characterized by a deep epipedon that is high in organic matter.
True
Organic matter distribution in the profile is a significant criterion for differentiating epipedons.
True
Oxisols are more highly weathered than are the soils of any other order.
True
The name of a subgroup indicates the order, suborder, and great group of which it is a member.
True
Vertisols are characterized by highly contents of swelling-type silicate clays.
True
You would be more apt to find a Gelisol in Alaska than in Iowa.
True
A soil has a think black A horizon, a distinct B horizon, has reasonably stable soil structure, and was formed under grassland natural vegetation. In which suborder is it most likely classed?
Udolls
In which soil order would recent alluvium most likely be a common parent material?
Ultisols