SSC 200: The ID and Classification of Soil
A pedon is a three-dimensional field unit occupying about 10,000 square meters (1 hectare) of land area. Select one: True False
False
Because soil development is just beginning in Entisols, these soils are generally less variable in properties than are those in the Andisol or Ultisol orders. Select one: True False
False
Epipedons are diagnostic subsoil horizons that are one of the primary means of classifying soils in the United States. Select one: True False
False
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. Select one: True False
False
Soils classified as Inceptisols have the least well developed profiles of those in any order in the Soil Taxonomy system. Select one: True False
False
Soils in the Oxisols order are deeply weathered and have deep subsurface horizons of calcium oxide. Select one: True False
False
Spodosols are generally less acidic and less sandy than are Alfisols. Select one: True False
False
The categories of Soil Taxonomy can be listed from the broadest (first) and most specific (last) as: order, suborder, great group, subgroup, series, family. Select one: True False
False
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. Select one: True False
True
An aquic soil moisture regime connotes a higher degree of soil moisture saturation than an ustic one. Select one: True False
True
An argillic horizon is a diagnostic horizon characterized by the subsurface accumulation of silicate clays. Select one: True False
True
Andisols are found mostly near recently active volcanoes. Select one: True False
True
Histosols generally have higher organic matter contents than Mollisols. Select one: True False
True
Mollisols are characterized by a deep epipedon that is high in organic matter. Select one: True False
True
Organic matter distribution in the soil is a significant criterion for differentiating epipedons. Select one: True False
True
Oxisols are more highly weathered than are the soils of any other order. Select one: True False
True
Russian scientists were the first to develop the concept of soils as natural bodies. Select one: True False
True
The broadest category of classification in Soil Taxonomy specifies 12 soil orders. Select one: True False
True
The family category focuses on properties affecting plant roots and suitability for engineering uses of soils. Select one: True False
True
The name of a subgroup indicates the order, suborder, and great group of which it is a member. Select one: True False
True
The two most significant characteristics of the classification system used in the United States are a unique system of terminology and focus on measurable soil properties as a primary basis for the classification. Select one: True False
True
Vertisols are characterized by high contents of swelling-type silicate clays. Select one: True False
True
You would be more apt to find You would be more apt to find an Gelisol in Alaska than in Iowa. Select one: True False
True
Soils in this order are commonly sandy in texture, quite acidic and develop primarily under coniferous trees in cool to cold climates. Select one: a. Spodosols b. Andisols c. Ultisols d. Mollisols e. Alfisols
a. Spodosols
Soils in which of the following soil suborders would most likely have a prominent E horizon under the A horizon? Select one: a. Udalfs b. Orthents c. Udolls d. Aquepts
a. Udalfs
In soils of which great group would you most likely find wide surface cracks during periods of dry weather? Select one: a. Kandiaquults b. Calciusterts c. Argiaquolls d. Albaqualfs e. Haplustox
b. Calciusterts
Soils in which of the following suborders would be more likely to occur in Minnesota than in Texas? Select one: a. Fluvents b. Cryolls c. Usterts d. Cambids e. Udalfs
b. Cryolls
In which of the following epipedons is the organic matter level generally lowest? Select one: a. histic b. ochric c. melanic d. umbric e. mollic
b. ochric
Investigating the soils of northern Canada on summer, you dig a soil pit easily though fairly uniform peat material until, at 75 cm deep, your shovel hits a layer that is frozen solid. Into which type of soil are you most likely digging? Select one: a. Cryent b. Fibrist c. Histel d. Histosol e. Cryert
c. Histel
The nomenclature of Soil Taxonomy is characterized by all but which one of the following statements? Select one: a. The names of the orders all end with the letters sols. b. The subgroup name also tells you the great group, suborder, and order names. c. The names give a clear indication of the modes of genesis of the soil. d. Soil names (except for series level) identifies major soil characteristics. e. The names are based on measurable properties and not on presumed modes of genesis.
c. The names give a clear indication of the modes of genesis of the soil.
You are seeking a soil with high clay content but one that is not sticky when wet nor hard and cloddy when dry. In which of the following suborders would you most likely find this soil? Select one: a. Cambids b. Aquands c. Ustox d. Udert
c. Ustox
Which of the following describes a soil that likely exists and contains a significant content of low activity clays? Select one: a. a Mollisols in Central Brazil b. an Inceptisol in Mississippi c. an Ultisol in the Congo River basin in Africa d. an Alfisol in New York e. an Oxisol in Minnesota
c. an Ultisol in the Congo River basin in Africa
The map units on a detailed soil map on Web Soil Survey are most likely to be labeled with names from which category of Soil Taxonomy? Select one: a. subgroup b. order c. series d. great group e. suborder
c. series
In which soil orders would recent alluvium most likely be a common parent material? Select one: a. Alfisols b. Aridisols c. Andisols d. Entisols e. Ultisols
d. Entisols
If the soils are to be used for crop production, for which soil order would land drainage be most critical? Select one: a. Inceptisols b. Oxisols c. Aridisols d. Histosols e. Mollisols
d. Histosols
Soils in which of the following soil suborders would most likely have a prominent E horizon under the A horizon? Select one: a. Udolls b. Orthents c. Aquepts d. Udalfs
d. Udalfs
A soil pedon is ________. Select one: a. a category of Soil Taxonomy b. generally larger in area than a polypedon c. a diagnostic subsurface horizon prominent in arid regions and in sandy parent materials. d. a three-dimensional unit that embodies the primary characteristics of an individual soil e. a surface horizon used to characterize soil suborders and great groups
d. a three-dimensional unit that embodies the primary characteristics of an individual soil
Argillic horizons are characterized by ________. Select one: a. organic matter accumulation b. high level of Na+ ions c. impervious hardpan layers d. accumulation of silicate clays e. high levels of iron and aluminum oxides
d. accumulation of silicate clays
Soil scientists generally map the soils in a landscape by sampling the soil in ________. Select one: a. the center of the suspected soil mapping unit b. pre-determined a grid-like geometric pattern of evenly spaced points c. four soil pits, one dug in each corner of the area to be mapped d. auger holes made mostly near expected soil boundaries e. a computer-calculated pattern of random points
d. auger holes made mostly near expected soil boundaries
Soil scientists from which country first conceived the idea that soils were natural bodies? Select one: a. Great Britain b. United States c. France d. Belgium e. Russia
e. Russia
Which of the following diagnostic horizons would likely not restrict root growth in soils? Select one: a. salic b. fragipan c. placic d. petrocalcic e. albic
e. albic
Which soil moisture regime has the highest soil moisture levels? Select one: a. aridic b. ustic c. udic d. xeric e. aquic
e. aquic
Which of the following subsurface diagnostic horizons would you expect to find in a highly weathered soil of the humid tropics? Select one: a. salic b. cambic c. natric d. spodic e. oxic
e. oxic
Which of the following categories of Soil Taxonomy provides the greatest specificity of soil properties? Select one: a. family b. order c. great group d. suborder e. series
e. series
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? Select one: a. ustalfs b. aquents c. cambids d. udults e. udolls
e. udolls
