Soils 3
Udolls
A soil has a thick 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?
Soil pedon
A three-dimensional unit that embodies the primary characteristics of an individual soil
Calcic
Accumulation of CaCO3 or CaCO3*MgCO3
Kandic
Accumulation of low-activity clays
Accumulation of silicate clays
Argillic horizons are characterized by _
Duripan
Hard pan, strongly cemented by silica
Histosols
If the soils are to be used for crop production, for which soil order would land drainage be most critical
Ochric
In which of the following epipedons is the organic matter level generally lowest?
Entisols
In which soil orders would recent alluvium most likely be a common parent material?
Albic
Light-colored, clay and Fe and Al oxides mostly removed
Umbric
Same as mollic except low base saturation
Argillic
Silicate clay accumulation
Spodosols
Soils in this order are commonly sandy in texture, quite acidic and develop primarily under coniferous trees in cool to cold climates
Series
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?
Mollic
Thick, dark-colored, high base saturation, strong structure
Ochric
Too light-colored, low organic content or thin to be mollic; may be hard and massive when dry
Histic
Very high in organic content, wet during some part of the year
Ultisol in the Congo River
Which of the following describes a soil likely to contain a significant content of low activity clays?
Oxic
Which of the following subsurface diagnostic horizons would you expect to find in a highly weathered soil of the humid tropics?
Aquic
Which soil moisture regime has the highest soil moisture elvels?
False
tf A pedon is a 3 dimensional field unit occupying about 1000 square meters of land area
True
tf A polypedon or individual soil is a group of closely related pedons that conceptually approximates what in the US is called a soil series
True
tf An aquic soil moisture regime connotes a higher degree of soil moisture saturation than an ustic one
True
tf An argillic horizon is a diagnostic horizon characterized by the subsurface accumulation of silicate clays
True
tf Andisols are found mostly near recently active volcanoes
False
tf For agricultural use in a given region, a soil with an ochric epipedon could generally be expected to be more productive than one with a mollic epipedon
True
tf Histosols generally have higher organic matter contents than Mollisons
True
tf Mollisols are characterized by a deep epipedon that is high in organic matter
True
tf Organic matter distribution in the profile is a significant criterion for differentiating epipedons
True
tf Oxisols are more highly weathered than the soils of any other order
True
tf The categories of soil taxonomy can be listed from the broadest and most specifice as: order, suborder, great group, subgroup, family, series
True
tf The name of a subgroup indicates the order suborder, and great group of which it si a member
True
tf Vertisols are characterized by high contents of swelling-type silicate clays
True
tf You would be more apt to find a Gelisol in Alaska than in Iowa
